"John Gould Bird Print Reproductions" [by Gordon C. Sauer], advertising sales, Box: 21, Folder: 45-50. Sauer's Gouldiana Research about John Gould and other papers, MS 304. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/204758 Accessed January 25, 2025.