“The Encyclopedia of Early American Vocal Groups – 1850 to 1950” – information on over 1500 vocal groups – a 15,000+ entry Discography. Nominee in 2014 for Association for Recorded Sound Collections Award for Excellence in Historical Recorded Sound Research. –www.harmonysongs.com. “The Comedian Harmonists: The Last Great Jewish Performers in Nazi Germany” – the only English language biography of this famous German singing group that was forced by the Nazis to disband in 1935 because three of the six members were Jewish - www.comedianharmonistsbook.com “Who Sang Our Songs?” – a Songography of 1950s R&B and doo-wop music. Over 30,000 entries. Available at www.oldies.com Classic Urban Harmony site of Dr. Charles and Pamela Horner – www.classicurbanharmony.net Tony Fournier’s Vocal Group Harmony web site – www.vocalgroupharmony.com Marv Goldberg’s site with many great articles – www.uncamarvy.com