Jardine [William] original Drawings G.C.S. [Gordon C. Sauer] Collection, Box: 21, Folder: 30. 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/204748 Accessed January 25, 2025.