^F. C. DeCoste, Bernard Schwartz, The Holocaust's ghost: writings on art, politics, law, and education, 80, 2000. "Others who died in Auschwitz, often via Holland and Terezin, were Alfred Kropf, a conductor from Stettin; Magda Spiegel, a Frankfurt contralto; and composer James Simon, a student of Max Bruch."
^Peter Hugh Reed, American Record Guide, No. 16, 1949
^Dinah Shelton, Encyclopedia of genocide and crimes against humanity, 2, 2005. Quote: "However, among them are: the baritone and cantor Erhard E. Wechselmann, murdered in Auschwitz; the contralto Magda Spiegel, murdered in Auschwitz; Richard Breitenfeld, a member of the Frankfurt opera ensemble, murdered in Theresienstadt"
^Great singers, from the seventeenth century to the present day Kurt Pahlen - 1974 Ottilie Metzger-Lattermann, who before 1914 had sung in all the important opera-houses and at Bayreuth, died in Auschwitz; the baritone Richard Breitenfeld, also a Wagner lead, in Theresienstadt.
