This article contains a representative list of notable databases and search engines useful in an academic setting for finding and accessing articles in academic journals, institutional repositories, archives, or other collections of scientific and other articles. Databases and search engines differ substantially in terms of coverage and retrieval qualities.[1] Users need to account for qualities and limitations of databases and search engines, especially those searching systematically for records such as in systematic reviews or meta-analyses.[2] As the distinction between a database and a search engine is unclear for these complex document retrieval systems, see:
The terms "free", "subscription", and "free & subscription" will refer to the availability of the website as well as the journal articles used. Furthermore, some programs are only partly free (for example, accessing abstracts or a small number of items), whereas complete access is prohibited (login or institutional subscription required).
The "Size" column denotes the number of documents (articles, publications, datasets, preprints) rather than the number of citations or references. The database itself should be the primary source of statistics, and if it is not accessible, the independent estimates released as journal papers should be. Notably, Google Scholar does not offer such detail, but the database's size has been calculated.[2]
The main academic full-text databases are open archives or link-resolution services, although others operate under different models such as mirroring or hybrid publishers. Such services typically provide access to full text and full-text search, but also metadata about items for which no full text is available.
This list focuses on general-purpose services; OpenDOAR can be used to find thousands of open-access repositories. The table is sorted by the number of works for which full-text is made available.
| Name | Discipline(s) | Size (full-texts) | Description | Access cost | Open data | Provider(s) |
|---|---|---|---|---|---|---|
| Internet Archive Scholar | Multidisciplinary | 25,000,000 | Focus on fulltext search of open access journals and conference proceedings | Free | Yes | Internet Archive |
| CORE[3] | Multidisciplinary | 9,800,000[4] (207,000,000 metadata[5]) | A full text aggregator of all open access papers from repositories (institutional, subject, preprints, etc.) and journals. Around 20 million monthly active users. | Free | No[4] | Open University |
| CiteSeerX[6] | Multidisciplinary | 8,401,126 | Replaced CiteSeer, and ChemXSeer. Mainly Computer science, Statistics, Mathematics. | Free | Semi-free[7] | Pennsylvania State University |
| Paperity[8] | Multidisciplinary | 10,500,000 | Full-text aggregator of open access journals and papers (>17,000 journals) from all academic disciplines. | Free | No[9] | Paperity Sp. z o.o. |
| Semantic Scholar | Multidisciplinary | 8,100,000[10] (200,000,000 metadata[11]) | Mostly computer science and biomedical publications. Powered by semantic analysis. | Free | Semi-free[10] | Allen Institute for Artificial Intelligence |
| Europe PMC[12] | Biomedical | 7,500,000 (39,000,000 metadata) | Abstracts & full text ( 7.5 million) biomedical and life sciences articles (Dec 2020). Includes text mining tools and links to external molecular and medical data sets. | Free | Yes | EMBL-EBI |
| PubMed Central (PMC)[13] | Biomedical, life sciences | 7,500,000 | Free full-text archive of publications and preprints | Free | Yes | NIH, NLM |
| ResearchGate | Multidisciplinary | 4,000,000[citation needed] | Commercial social networking site for scientists and researchers. Over 19 million registered users that share their articles, datasets and other research output. | Free | No | ResearchGate GmbH |
| SSRN: Social Science Research Network | Social science | 950,733 | Research papers from more than 55 disciplines | Free & Subscription | No | Elsevier |
| HAL | Multidisciplinary | 760,000 (2,000,000 metadata)[14] | An open-access database for French researchers. Organized into institution and domain portals. | Free | Yes | CNRS's Centre pour la Communication Scientifique Directe (CCSD) |
| RePEc: Research Papers in Economics[15] | Economics | 90,000 (3,200,000 metadata)[16] | Working papers, journal articles, books, books chapters and software components (including 1.2 million full-text articles) | Free | IDEAS: Federal Reserve Bank of St. Louis
EconPapers: Örebro University School of Business | |
| PhilPapers | Philosophy | 70,000[17] (2,540,317 metadata) | Index journals, books, open access archives, and personal pages maintained by academics | Free | PhilPapers | |
| ERIC: Educational Resource Information Center[18] | Education | Unknown (1,500,000 metadata) | Education literature and resources dating back to 1966. | Free & Subscription | United States Department of Education (available by subscription from OCLC, CSA) | |
| Synthical[19][20] | Multidisciplinary | 3,000,000[21] | Pre-prints, mainly computer science, mathematics, statistics, chemistry, and biology. | Free | Yes | Synthical |
| Zendy[22] | Multidisciplinary | Unknown (31,266,280[23] | Focus on scholarly content including full-text papers, conference proceedings, indexed journals, books, and book chapters from open access sources. Content is available in 38 languages, covering various subjects and disciplines. | Free & Subscription | Yes | Knowledge E, Zendy |
| Name | Discipline(s) | Size | Description | Access cost | Provider(s) |
|---|---|---|---|---|---|
| AGRIS: Agricultural database[24] | Agriculture | 12,021,578 | Covers agriculture, forestry, animal husbandry, aquatic sciences and fisheries, human nutrition, extension literature from over 100 countries. Indexes unpublished scientific and technical reports, theses, conference papers, government publications. | Free | FAO |
| Arachne[25] | Archaeology, Art history | 4,485,534 | 2.4 million digital images from archive material, 1 million of books, 40,000 high quality scans of ancient sculptures, 300 volumes of ancient books with more than 60,000 pages | Free | DAI & University of Cologne |
| AMiner[26] | Computer Science | 265,034,285 | Online service used to index and search academic social networks | Free | Tsinghua University |
| Arts & Humanities Citation Index[27] | Arts, Humanities | 4,900,000 | Part of Web of Science. 1,800 journals across 28 arts & humanities disciplines. Records back from 1975 to present. | Subscription | Clarivate Analytics |
| Astrophysics Data System[28] | Astrophysics, Geophysics, Physics | 13,300,000 | Publications in Astronomy and Astrophysics, Physics, and the arXiv e-prints | Free | Harvard University |
| ATLA Religion Database[29] | Religious studies | 3,000,000 | Provides information on topics such as biblical studies, world religions, church history, and religion in social issues | Subscription | EBSCO Publishing |
| BASE: Bielefeld Academic Search Engine[30] | Multidisciplinary | 259,497,239 | Metadata for 260 million documents from more than 8,000 content providers | Free | Bielefeld University |
| Book Review Index Online | Book reviews | 5,600,000 | Reviews of periodicals and books – including those on tape and electronic media | Subscription | Thomson Gale |
| Books in Print | Books | 2,500,000 | Reviews covering over 2.5 million titles | Subscription | R. R. Bowker |
| CAB Abstracts | Applied life sciences | 10,000,000 | Bibliographic information service providing access to applied life sciences literature. | Subscription | CABI |
| CINAHL: Cumulative Index to Nursing and Allied Health[31] | Nursing, Allied Health | 7,800,000 | Journal articles about nursing, allied health, biomedicine and healthcare. Covers 5,500 journals (English and other language). | Subscription | EBSCO |
| CiNii[32] | Multidisciplinary | 22,000,000 | Database of articles in the Japanese language from 3600 journals | Free & Subscription | National Institute of Informatics |
| CNKI | Multidisciplinary | 160,000,000 | A Chinese bibliographic database | Free & Subscription | CNKI |
| CORE[3] | Multidisciplinary | 207,000,000[5] | Around 20 million monthly active users. | Free | Open University |
| Crossref[33] | Multidisciplinary | 111,231,936 | An official Digital Object Identifier (DOI) Registration Agency of the International DOI Foundation. Metadata about publications, datasets, grants, preprints from 17,633 members (journals, publishers, etc.) | Free | Crossref |
| DeepDyve | Multidisciplinary | 20,000,000 | Commercial website that sells access to scientific and scholarly articles from a large range of academic publishers (over 1700 journals). Limited free access. | Free & Subscription | DeepDyve |
| Dimensions[34][35] | Multidisciplinary | 302,000,000 | Publications, books and book chapters, preprints and conference proceedings (linked to data sets, funding, publications, patents, clinical trials, and policy documents). Based on CrossRef. Contains citation-based indicators and Altmetric attention scores. | Free & Subscription | Digital Science & Research Solutions Ltd |
| Directory of Open Access Journals (DOAJ)[36] | Multidisciplinary | 8,265,735 | Articles from 18,652 open access journals (Dec 2022) | Free | Infrastructure Services for Open Access (IS4OA) |
| DBLP[37] | Computer science | 5,387,041 | Comprehensive list of papers from major computer science conferences and journals | Free | Leibniz Center for Informatics and University of Trier |
| EconBiz[38] | Economics | 10,000,000 | Covers journals, working papers & conferences in business studies and economics | Free | ZBW- German National Library of Economics– Leibniz Information Centre for Economics (ZBW) |
| EconLit[39] | Economics | 1,600,000 | Covers articles and other materials dating back to 1969 | Subscription | American Economic Association (available from EBSCOhost, ProQuest, OVID, and AEA) |
| EMBASE[40] | Biomedicine, Pharmacology | 32,000,000 | Biomedical database with a focus on drug and pharmaceutical research. Rrecords from over 8,500 journals (1947–present). | Subscription | Elsevier |
| FSTA – Food Science and Technology Abstracts | Food science, Food technology, Nutrition | 1,500,000 | The database of information on food science, food technology and nutrition | Subscription | IFIS Publishing (available via EBSCOhost, IHS Inc., Ovid, Proquest Dialog, STN and Web of Science) |
| GeoRef[41] | Geosciences | 4,000,000 | Records from 3,500 journals in 40 languages | Subscription | American Geosciences Institute |
| Google Scholar[1] | Multidisciplinary | 389,000,000 | The biggest academic database & search engine (over 390 million records, unofficial estimate) | Free | |
| Informit | Multidisciplinary | 8,000,000 | Australasian aggregator of bibliographic databases and journals | Subscription | RMIT Training Pty Ltd (RMIT Training) |
| Inspec | Physics, Engineering, Computer Science | 18,000,000 | Contains records in physics, electrical engineering, electronics, communications, control engineering, information technology, manufacturing, production, and mechanical engineering. | Subscription | IET |
| International Nuclear Information System (INIS)[42] | Nuclear Physics, Nuclear Energy, Medical Physics | 4,600,000 | A leading bibliographic and grey literature repository covering all areas of nuclear science and technology. | Free | International Atomic Energy Agency |
| International Philosophical Bibliography | Philosophy | 1,000,000 | Focus on the history of philosophy and continental philosophy. | Subscription | Université Catholique de Louvain (available from Peeters Publishers) |
| J-Gate[43] | Multidisciplinary | 71,692,382 | J-Gate is an electronic gateway to global e-journal literature (articles from 58,000 journals) | Free & Subscription | Informatics India Ltd |
| The Lens[44] | Multidisciplinary | 228,108,724 | Serves global patent and scholarly knowledge as a public good to inform science and technology enabled problem solving. | Free & Subscription | Cambia |
| MathSciNet | Mathematics | 3,600,000 | Records from 650 math journals (early 1800–present) | Subscription | American Mathematical Society |
| MEDLINE | Medicine, Healthcare | 26,000,000 | Easy-to-use interface to search and retrieve citations and abstracts from 5,200 journals via MeSH vocabulary | Free | NLM |
| MyScienceWork | Multidisciplinary | 90,000,000 | Database includes more than 90 million scientific publications and 12 million patents. | Free | MyScienceWork Inc |
| National Diet Library Collection | Multidisciplinary | 44,187,016 | Japanese. Catalog for the National Library of Japan. | Free | National Diet Library |
| OAIster[45] | Multidisciplinary | 30,000,000 | Covers records contributed by over 1,500 organizations | Free | OCLC |
| OpenAIRE Graph | Multidisciplinary | 242,000,000 | Scientific Knowledge Graph aggregating, deduplicating, enriching metadata of publications, research data, research software, and other products, with citations links and links to funders and grants - core service in support of the European Open Science Cloud | Free | OpenAIRE AMKE (not-for-profit) |
| OpenAlex | Multidisciplinary | 205,000,000[46] | Index and metadata for all scholarly output. | Free | OurResearch |
| PsycINFO | Psychology | 3,700,000 | Focus at behavioral science and mental health. Coverage 1887–present. | Subscription | APA |
| PubMed[47] | Biomedical, life sciences | 30,000,000 | A database primarily of references and abstracts on life sciences and biomedical topics. Includes MEDLINE, PubMed Central, and Bookshelf. | Free | NIH, NLM |
| RSWBplus[48] | Civil Engineering, Architecture | 1,600,000 | Bibliographic database for planning and building related publications, chronological coverage since 1975. Focus: German-language publications, journal articles, book chapters, conference papers, research reports. | Subscription | Fraunhofer IRB |
| Russian Science Citation Index | Multidisciplinary | 35,409,829 | A bibliographic database of scientific publications in Russian | Free | Scientific Electronic Library |
| ScienceOpen | Multidisciplinary | 66,000,000 | Natural and physical sciences, social sciences, and humanities. Incorporates arXiv, PubMed, and SciELO. Integrated with ORCID Altmetric uids. Articles from >25,000 journals. | Free | ScienceOpen Inc. |
| Scopus[49] | Multidisciplinary | 78,000,000 | Records from over 20,500 titles from over 5,000 international publishers | Subscription | Elsevier |
| Web of Science[49] | Multidisciplinary | 171,000,000 | Includes other products, such as Social Sciences Citation Index, Science Citation Index, Biological Abstracts & The Zoological Record | Subscription | Clarivate Analytics |
| Zasshi Kiji Sakuin: Japanese Periodicals Index | Multidisciplinary | 6,600,000 | Scholarly articles in Japanese | Free & Subscription | National Diet Library |
| Zentralblatt MATH | Mathematics | 4,000,000 | Mainly reviews and abstracts. | Free | FIZ Karlsruhe |
| The Zoological Record | Zoology | 3,500,000 | Unofficial register of scientific names & papers in zoology. Coverage 1864–present. | Subscription | Clarivate Analytics |
Services with less than a million searchable records.
| Name | Discipline(s) | Size | Description | Access cost | Provider(s) |
|---|---|---|---|---|---|
| Academic Search[50] | Multidisciplinary | Several versions: Complete, Elite, Premier, and Alumni Edition | Subscription | EBSCO Publishing | |
| Aerospace & High Technology Database | Aerospace, Aeronautics, Astronautics | Provides indexing and abstracts from current serial and non-serial titles, including content from AIAA and NASA | Subscription | ProQuest | |
| African Journals OnLine (AJOL)[51] | Multidisciplinary | 185,649 | Scholarly journals published in Africa | Free & Subscription | AJOL |
| AgeLine[50] | Sociology, Gerontology | Includes information on aging-related topics, including economics, public health and policy | Subscription | EBSCO Publishing | |
| AGRICOLA: Agricultural Online Access[52] | Agriculture | Provides public access to information on agriculture and allied fields (17th century - present) | Free & Subscription | NAL (free access NAL, subscription access ProQuest, OVID) | |
| Airiti | Multidisciplinary | Chinese e-content provider of Chinese academic e-journals, Taiwanese academic e-journals, classical art images | Subscription | Airiti Inc. | |
| Analytical Abstracts[53] | Chemistry | 505,481 | Selection of analytical chemistry articles published by the Royal Society of Chemistry (around 100 journals) | Subscription | RSC |
| Anthropological Index Online[54] | Anthropology | Indexes only (no abstracts or full-text) the anthropology journals received by The Anthropology Library at The British Museum | Free & Subscription | RAI | |
| Anthropological Literature[55] | Anthropology, Archaeology | 670,000 | An index of journals primarily from Tozzer Library, as well as other open-access journals (660 journals with more than 670,000 articles) | Free & Subscription | Harvard University (non-Harvard access provided by OCLC) |
| ArchiveGrid | Multidisciplinary | Directory of archival materials from American and international institutions, including over five million records | Free | WorldCat | |
| ASCE Library | Civil Engineering | 150,000 | All civil engineering disciplines including structural engineering, geotechnical engineering, transportation engineering, construction engineering, environmental engineering, engineering mechanics, sustainability, water resources, irrigation. hydraulics, hydrology, waterways, urban planning, cold regions ... | Free & Subscription | ASCE |
| AULIMP: Air University Library's Index to Military Periodicals | Military Science | The articles, news items, book reviews and editorials from 63 English language military and aeronautical periodicals | Free | Air University | |
| Biological Abstracts[56] | Biology | Biomedical research literature published from more than 4,000 journals internationally. | Subscription | Thomson Reuters | |
| Cabells | Multidisciplinary | 35,000 | Database to discover, evaluate, and compare journals. Journal listings include publication info, submission guidelines, and metrics. | Subscription | Cabells |
| Chemical Abstracts Service | Chemistry | Approximately 8,000 journals, technical reports, dissertations, conference proceedings, and new books | Subscription | ACS | |
| Chinese Social Sciences Citation Index[57] | Social sciences | 60,000 | Covers about 500 Chinese academic journals of humanities and social sciences | Subscription | Nanjing University |
| CHBD: Circumpolar Health Bibliographic Database[58] | Medicine | 7,900 | Contains records describing publications about all aspects of human health in the circumpolar region | Free | University of Calgary |
| Civil engineering database | Civil engineering | 270,000 | A bibliographic database covering all of ASCE's publications since 1872 | Free | American Society of Civil Engineers |
| Cochrane Library | Medicine, Healthcare | Includes reviews of research to promote evidence-based healthcare. | Subscription | Wiley Interscience | |
| Current Contents | Multidisciplinary | Part of Web of Science. Contains 7 discipline-specific subsets. | Subscription | Clarivate Analytics | |
| DSI: Stuttgart_Database_of_Scientific_Illustrators_1450–1950 | Multidisciplinary | 13,096 | bio-bibliographic data about illustrators of published scientific works from c.1450 until 1950 in 100+ countries, with 20 search fields | Free | compiled by the Section for History of Science & Technology, University_of_Stuttgart |
| Index Copernicus[59] | Multidisciplinary | Contains over 2,500 journals (including 700 journals from Poland). | Free | Index Copernicus Ltd | |
| Information Bridge: Department of Energy Scientific and Technical Information | Multidisciplinary | 266,000 | Provides free public access to over 266,000 full-text documents and bibliographic citations of Department of Energy (DOE) research report literature. Documents are primarily from 1991 forward. | Free | DOE (OSTI) |
| Indian Citation Index[60] | Multidisciplinary | 860,000 | Covers articles from 1100+ journals from India from scientific, technical, medical, and social sciences | Subscription | ICI |
| IARP[61] | Multidisciplinary | Open-access knowledge management system incorporating grants, publications, conferences in natural and social & behavioral sciences | Free | Volunteer Collaboration | |
| INSPIRE-HEP | Physics, (High Energy) | An open access digital library for the field of high energy physics (HEP) (operates since the 1970s) | Free | CERN, DESY, Fermilab, SLAC and IHEP | |
| International Directory of Philosophy | Philosophy | 37,000 | Contains information on university philosophy departments and programs, philosophical societies, research centers, journals, and philosophy publishers in the U.S., Canada, and approximately 130 other countries. | Free & Subscription | Philosophy Documentation Center |
| International Medieval Bibliography[62] | Medieval studies | 440,000 | A multidisciplinary bibliographic database covering Europe, North Africa and the Middle East for the entire period from AD 300 to 1500 | Subscription | Leeds University (available from Brepols Publishers) |
| JournalSeek | Multidisciplinary | Catalogues over 39,000 journals' information (the description, aims, scope, journal abbreviation, journal homepage link, subject category and ISSN). | Free & Subscription | Genamics | |
| Jurn | Multidisciplinary | Index property and open access journals in the arts, humanities, ecology, science, biomedical, business and economics. | Free | David Haden | |
| L'Année philologique | Classical studies | Over 860,000 bibliographical entries, including keywords, abstracts, and links to the full text. | Subscription | Société Internationale de Bibliographie Classique (available from Brepols Publishers) | |
| LexisNexis | Law | Electronic database for legal and public-records related information | Subscription | Reed Elsevier | |
| Lingbuzz | Linguistics | 550,000 | A free archive of linguistics articles, with a focus on syntax, semantics, phonology and morphology | Free | University of Tromsø |
| Linguamatics | Medicine, Healthcare, Patents | Interface for searching MEDLINE, ClinicalTrials.gov, FDA Drug Labels, PubMed Central, and Patent Abstracts. | Subscription | Linguamatics | |
| Logeion | Classical Studies | An open-access database of Latin and Ancient Greek dictionaries | Free | University of Chicago | |
| Mendeley[63] | Multidisciplinary | N/A | Crowdsourced database of research documents. Over 100M documents uploaded by the researchers plus data from repositories (e.g. PubMed and arXiv) | Free & Subscription | Elsevier |
| National Criminal Justice Reference Service | Criminology, Sociology | 225,000 | Abstracts of scholarly journal articles, agency and NGO reports, audiovisual products, and conference proceedings. | Free | United States Department of Justice, Office of Justice Programs |
| OpenGrey | Grey literature | 700,000 | Indexes European grey literature | Free | Institut de l'information scientifique et technique |
| ORCID[64] | Multidisciplinary | An open and independent registry for contributor identification in research and academic publishing. List: biography, education, employment, works, grants, peer-review. Over 9.3 million profiles. | Free | ORCID Inc. | |
| Philosophy Documentation Center eCollection | Applied ethics, Philosophy, Religious studies | Journals, series, conference proceedings, and other works from several countries online | Free & Subscription | Philosophy Documentation Center | |
| POIESIS: Philosophy Online Serials | Philosophy, applied ethics, religious studies | Journals and series, online access for institutions with print | Free & Subscription | Philosophy Documentation Center | |
| Publons[65] | Multidisciplinary | Service for academics to track their peer review and editorial contributions for academic journals. Merged with ResearcherID | Free | Clarivate Analytics | |
| PubPsych | Psychology | 800,000 | Datasets and offers, where available, full-text linking, links to additional information and link resolving | Free | Leibniz Institute for Psychology Information |
| Readers' Guide to Periodical Literature | Literature | Reference guide to articles in >470 periodical magazines and journals, organized by article subject (1890 to present) | Subscription | H. W. Wilson Company | |
| Rock's Backpages[66] | Music | 40,000 | Primary documents from the history of rock and roll. Articles, including interviews, features and reviews, which covered popular music from blues and soul | Free & Subscription | Backpages Ltd |
| SafetyLit | Multidisciplinary | 640,000 | >35 distinct professional disciplines (architecture - zoology) relevant to preventing unintentional injuries, violence, and self-harm | Free | SafetyLit Foundation |
| Science.gov | Multidisciplinary | A gateway to government science information and research results from over 60 databases, over 2,200 websites, and over 200 million pages. | Free | United States Government | |
| Science Citation Index[67] | Multidisciplinary | Part of Web of Science. 24,000+ journals across 254 subject disciplines. | Subscription | Clarivate Analytics | |
| Scientific Information Database (SID) | Engineering & Technology, Medical Science, Basic Science, Human Sciences | An Iranian index of academic journals and access to full text or metadata | Free | Scientific Information Database | |
| SCIndeks - Serbian Citation Index | Multidisciplinary | 80,000 | A bibliographic database, a national citation index, an Open Access full-text journal repository and an electronic publishing platform. Articles from >230 journals. | Free | CEON/CEES - Centre for Evaluation in Education and Science |
| SNAC (Social Networks and Archival Contexts) | Multidisciplinary | Directory of archival materials grouped by subject entity | Free | ||
| Social Sciences Citation Index | Social science | Part of Web of Science | Subscription | Clarivate Analytics | |
| Socolar | Multidisciplinary | Scholarly open access resources in different language (mainly Chinese) | Free & Subscription | China Educational Publications Import and Export Corporation | |
| Ulrich's Periodicals Directory | Multidisciplinary | 336,000 | Provides serials for periodicals | Subscription | ProQuest |
| VET-Bib | Social Science, Education | 80,000 | European vocational education and training (VET) literature | Free | Cedefop |
| WestLaw | Law | Over 40,000 databases of case law, state and federal statutes, administrative codes, newspaper and magazine articles, public records, law journals, law reviews, treatises, legal forms and other information resources | Subscription | Thomson Reuters | |
| WorldCat[68] | Multidisciplinary | Unified catalog of member libraries' catalogs | Free & Subscription | OCLC Inc. | |
| WorldWideScience | Multidisciplinary | A union catalog that itemizes the collections of 17,900 libraries in 123 countries | Free & Subscription | DOE (OSTI) |
Content by most academic publishers is indexed by CrossRef, DOAJ and/or DataCite. Some publishers are also listed separately in the table below.
| Name | Discipline(s) | Size | Description | Access cost | Provider(s) |
|---|---|---|---|---|---|
| Association for Computing Machinery Digital Library | Computer Science, Engineering | 2,892,573 | Collection of all ACM publications, including journals, conference proceedings, technical magazines, newsletters and books | Subscription | Association for Computing Machinery |
| Analytical Sciences Digital Library[69] | Analytical chemistry | A collection of peer-reviewed electronic resources on chemical measurements and instrumentation | Free | NSDL and ACS | |
| Bibliographie de civilisation médiévale | Medieval studies | A bibliography of monographs on the Middle Ages. As of 2018, it contains about 65,000 fully classified bibliographic records. | Subscription | University of Poitiers (available from Brepols Publishers) | |
| BioOne | Biology, Ecology, Environmental Science | Full-text from >180 scientific journals in Biodiversity Conservation, Biology, Ecology, Environmental Science, Entomology, Ornithology, Plant Science, and Zoology. | Free & Subscription | BioOne | |
| IEEE Xplore | Computer Science, Engineering, Electronics | 5,360,654 | Over 5 million records. | Subscription | IEEE |
| IngentaConnect | Multidisciplinary | 5,000,000 | Covers articles from 13,000 journals | Free & Subscription | Ingenta |
| JSTOR: Journal Storage | Multidisciplinary | 12,000,000 | Journal articles, books, and primary sources in 75 disciplines (1870–present) | Free & Subscription | JSTOR |
| OpenEdition.org | Humanities, social science | 60,000 | Offers four international-scale publication and information platforms in the humanities and social sciences (10,661 books, 549 journals, 3793 blogs, 45,591 events). | Free | Cléo (UMS 3287) CNRS EHESS University of Avignon |
| Project MUSE | Humanities, social science | MUSE's online journal collections are available on a subscription basis to academic, public, special, and school libraries. More than 2,500 libraries worldwide subscribe. | Subscription | Project MUSE, Johns Hopkins University Press | |
| SciELO | Multidisciplinary | 573,525 | Database and a model for cooperative electronic publishing in developing countries (mostly South America and Africa). Indexes >1700 journals. | Free | FAPESP, CNPq and BIREME |
| ScienceDirect | Science including Medicine | 18,000,000 | Content from more than 4,000 academic journals and 30,000 e-books | Subscription | Elsevier |
| SpringerLink | Multidisciplinary | 13,859,779 | Journals, books, series, protocols, reference works and proceedings | Free & Subscription | Springer |
The following services are no longer operating; this may be because they were not updated, abandoned entirely, replaced by other, etc.
| Name | Discipline(s) | Description | Access cost | Provider(s) |
|---|---|---|---|---|
| Bioinformatic Harvester | Biology, Bioinformatics | A meta search engine for 50 major bioinformatic databases and projects. Project appears to be not available anymore. | Free | Liebel-Lab KIT from Karlsruhe Institute of Technology |
| citeULike | Computer science | Not available. Ceased operations as of March 30, 2019 | Free | Oversity Ltd. |
| ChemXSeer | Chemistry | The project seems abandoned in 2018 | Free | Pennsylvania State University |
| citebase Search | Mathematics, Computer science, Physics | Semi-autonomous citation index of free online research. Not available; ceased operations in 2013 | Free | University of Southampton |
| citeSeer | Computer Science | Replaced by citeSeerX. | Free | Pennsylvania State University |
| Chemisches Zentralblatt Structural Database | Science, Chemistry | Web-based retrieval application that provided language-independent access to the information contained in Chemisches Zentralblatt | Subscription | InfoChem |
| CogPrints: Cognitive Sciences Eprint Archive | Multidisciplinary | An electronic archive for self-archive papers in Psychology, Neuroscience, Linguistics, Computer Science, Philosophy, Biology, and Medicine. Contains over 2000 free articles. Not updated since 2017. | Free | University of Southampton |
| The Collection of Computer Science Bibliographies | Computer science | One of the oldest (if not the oldest) bibliography collections freely accessible on the Internet (founded 1993). Contains 4.2 million records. Not updated since 2017. | Free | Alf-Christian Achilles |
| Current Index to Statistics | Statistics | Limited free search. Not updated since 2017. | Subscription | American Statistical Association and the Institute of Mathematical Statistics |
| Ei Compendex | Engineering | Electronic version of Engineering Index | Subscription | Elsevier |
| GENESIS | Women's history | Descriptions of women's history collections from sources in the UK, as well as women's history websites. | Free | London Metropolitan University |
| Global Health[70] | Public Health | Specialist abstracting and indexing database dedicated to public health research and practice. Contains scientific records from 1973 to the present. | Subscription | CABI |
| HCI Bibliography | Human–computer interface | An electronic bibliography for most of HCI for researchers, developers, educators, and students. Over 126,000 publications. Not updated since 2018. | Free | Gary Perlman |
| International Bibliography of Humanism and the Renaissance | Renaissance studies | A bibliography of academic publications on European culture and history in the 16th and 17th centuries. It seems that the database is not available and not updated since 2013. | Subscription | Brepols Publishers |
| Meteorological and Geoastrophysical Abstracts | Meteorology, Astrophysics, Geology | Over 508,379 records from 654 journals. It seems that the database is not available and not updated since 2009. | Subscription | American Meteorological Society (available from Dialog and CSA). |
| Microsoft Academic[71] | Multidisciplinary | Covered publications from over 49,000 journals. Retired on December 31, 2021.[72] | Free | Microsoft |
| Philosophy Research Index | Philosophy | Index of books, journals, dissertations, and other documents. Merged with PhilPapers. | Subscription | Philosophy Documentation Center |
| POPLINE | Population, Family Planning | A collection of population, family planning and related reproductive health and development literature. Retired in 2019. | Free | Knowledge for Health, Center for Communication Programs, JHSPH |
| Questia: Online Research Library | Multidisciplinary | Emphasis on books and journal articles in the humanities and social sciences. Closed down on December 21, 2020 | Subscription | Questia |
| Science Accelerator | Multidisciplinary | A gateway to results of DOE research and development and major R&D accomplishments of interest to DOE. Not working from 2014 | Free | DOE |
| Sparrho | Multidisciplinary | Research articles and patents from 45k+ journals and preprint servers. Uses content recommendation concept. | Subscription | Distylled Ltd. |
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