"All This from a 5-cent Hamburger!: The Story of the White Castle System by E.W. Ingram, Sr., 1975, Box: 14, Folder: 6. David Katzman papers, RH MS 1186. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/560850 Accessed June 23, 2025.