Clifton Otto letter of introduction from Ray B. Duboc, President, The Western Insurance Companies, to Charles F. Thomas, Secretary-Manager, Western Underwriters Association, October 1, 1937, Box: 1, Folder: 4. Clifton Crain Otto collection of the Western Insurance Companies records, RH MS 1146. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/90819 Accessed May 11, 2024.