Article: "[The] Missing Volume of John Gould's Working Notebook for his 'Birds of Europe'", 1976, Box: 17, Folder: 35. 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/204609 Accessed June 02, 2024.