PSHTC, Cotter and Spradlin, Progress Report, OEG-0-70-1198 (607), Submitted, December 13, 1969, Box: 62, Folder: 21. University of Kansas Schiefelbusch Institute for Life Span Studies records, RG 35. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/455442 Accessed May 21, 2025.