Risley, Todd, Exploratory Behavior of the Profoundly Multi-Handicapped, 4136-1, February 25, 1982, Box: 68, Folder: 5. 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/455599 Accessed June 02, 2024.