"The Henkel memorial" by S. Stapleton (ed) - York, Pennslyvania: A. Stapleton, 1910, Box: 27, Volume: 95. Personal papers of Joseph M. Kellogg, PP 237. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/136916 Accessed May 20, 2024.