"A Half Century of Grain and Milling," By Frank A. Theis, before Kansas City Chamber of Commerce, April 27, 1938, Box: 22, Folder: 9. Frank A. Theis papers, RH MS 948. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/60809 Accessed July 18, 2025.