Stepping Back from Early Intervention: An Ethical Perspective, A. Turnbull and H.R. Turnbull, October 1985, Box: 16, Folder: 1. Personal papers of Rud Turnbull, PP 511. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/305381 Accessed June 16, 2025.