Family Support: Retrospective and Prospective, H.R. Turnbull and A. Turnbull in Mental Retardation in 21st Century, 2000, Box: 2, Folder: 108. Personal papers of Rud Turnbull, PP 511. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/304994 Accessed June 13, 2025.