Hunter - A Book On Chipmunks (1969), Spaceship Earth Series (1970-[19]71), How the Earth Evolved (1970), Box: 10, Folder: 26. Corporate Papers of the Robert Mills Literary Agency, MS 307. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/230269 Accessed November 23, 2024.