"John Gould's Prospectuses and Lists of Subscribers to his Works On Natural History: With an 1866 Facsimile" by Gordon C. Sauer, 1980, Box: 21, Folder: 34. 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/204752 Accessed January 15, 2025.