Niven - The Flight of the Horse (1978), The Fourth Profession (1970), A Gift From Earth (1966), The Green Marauder (1979), A Hole in Space (1973), Box: 15, Folder: 40. 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/230446 Accessed May 15, 2024.