Glancy, H. Mark (March 1995). "Warner Bros Film Grosses, 1921–51: the William Schaefer ledger". Historical Journal of Film, Radio and Television. 15 (1): 55–73. doi:10.1080/01439689500260031.
"Appendix 1: Warner Bros. Financial Data". Historical Journal of Film, Radio and Television. 15 (sup1): 1–31. March 1995. doi:10.1080/01439689508604551.