PSHTC, Cotter, Vance, Contingent Music Systems in classrooms to Improve Handicapped Children's Performance on Teaching Machine Programs, Submitted, March, 1970, Box: 62, Folder: 19. 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/455440 Accessed June 02, 2024.