Birr, Jack, A Regional Information System, Correspondence, July 9, 1973-June 7, 1974, Box: 4, Folder: 20. 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/452350 Accessed June 02, 2024.