Films discussed in the body of Weaver, Tom, Michael Brunas, and John Brunas. Universal Horrors: The Studio's Classic Films, 1931-1946. 2nd Ed. Jefferson, N.C: McFarland & Co, 2007.
See also the appendices (Universal Serial Horrors and Exclusions, Borderline Inclusions, Odds and Ends) as well as Shock! and Son of Shock.