"Bargain Books", "Bargain Books Biography", Edward R. Hamilton, 1990, 1992, Box: 8, Folder: 4. 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/204188 Accessed May 18, 2024.