found: Brahms, J. Ein deutsches Requiem [SR] p1972:container (Bernhard Sönnerstedt, baritone)
found: http://www.thecelebritycafe.com/birthdays/July/26/( Sönnerstedt, Bernhard; b. July 26, 1911)
found: Bach cantatas WWW site, July 31, 2008:Performers: Vocal; Short biographies (Bernhard Sönnerstedt; b. July 26, 1918, Norrhult, Sweden; d. Aug. 7, 1971; baritone) - http://www.bach-cantatas.com/
found: Kutsch/Riemens, 3. erw. Aufl.(Sönnerstedt, Bernhard; b. July 26, 1911, Nottebäk, near Norrhult, Småland Province, Sweden; d. Aug. 4, 1973, Stockholm; bass-baritone)
found: Sohlmans musiklexikon, 1975-1979(Sönnerstedt, Bernhard; b. July 27, 1911; d. Aug. 4, 1973; bass-baritone)