Dickson - Spacepaw (1966), The Space Swimmers (1962, 1965), Space Winners (1963, 1966, 1970), Box: 5, Folder: 29. 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/230136 Accessed May 23, 2024.