Reel to reel tape of New Harnischfeger RH-25 film "Introducing a Totally New Generation of Digging Equipment", undated, Box: 12, Folder: 7. Martin Tractor Company records, RH MS 864. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/154033 Accessed January 03, 2025.