David A. Otto person on right / Stan Roth person on left, Box: 1, item: 3, Page: 9. Study of the Middle Pennsylvanian Flora Found in the Buildex Quarry, Franklin County, Kansas, RH MS 1258. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/5886 Accessed May 18, 2025.