Program Project, Communication Research with Retarded Children, Joseph Spradlin, July 16, 1976, Box: 60, Folder: 10. 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/455380 Accessed July 08, 2025.