Miscellaneous; correspondence, 1964, 1966, 1969-72, 1974, 1978-80, 1982-83 & 1986-89, Box: 13, Folder: 5. Martin Tractor Company records, RH MS 864. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/154043 Accessed January 03, 2025.