G-hawk. Lawrence, Kansas: Department of Geology, University of Kansas, January 1939

G-hawk. Lawrence, Kansas: Department of Geology, University of Kansas, January 1939, Volume: Gilbert D460. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/526039 Accessed December 27, 2025.