Warner Bros financial information in The William Shaefer Ledger. See Appendix 1, Historical Journal of Film, Radio and Television, (1995) 15:sup1, 1-31 „Appendix 1”. Historical Journal of Film, Radio and Television. 15: 1—31. 1995. doi:10.1080/01439689508604551.
Glancy, H Mark (1995). „Warner Bros Film Grosses, 1921–51: the William Schaefer ledger”. Historical Journal of Film Radio and Television. 15: 55—73. doi:10.1080/01439689500260031.