@misc{ enwiki:1215862139, author = "{Wikipedia contributors}", title = "Quadrature amplitude modulation --- {Wikipedia}{,} The Free Encyclopedia", year = "2024", url = "https://en.wikipedia.org/w/index.php?title=Quadrature_amplitude_modulation&oldid=1215862139", note = "[Online; accessed 23-July-2024]" }
url
(\usepackage{url}
somewhere in the preamble), which tends to give much more nicely formatted web addresses, the following may be preferred:
@misc{ enwiki:1215862139, author = "{Wikipedia contributors}", title = "Quadrature amplitude modulation --- {Wikipedia}{,} The Free Encyclopedia", year = "2024", howpublished = "\url{https://en.wikipedia.org/w/index.php?title=Quadrature_amplitude_modulation&oldid=1215862139}", note = "[Online; accessed 23-July-2024]" }