"The greatest Norman conquest" by James van Wyck Osborne - New York: E.P. Dutton and Company Incorporated 1937, Box: 25, Volume: 46. Personal papers of Joseph M. Kellogg, PP 237. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/136874 Accessed March 11, 2025.