Risley, Todd and Mike Cataladeo, Norms of Living Environments for the Retarded, HD-08043, January 31, 1973, Box: 67, Folder: 26. 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/455578 Accessed May 22, 2025.