Niven - Tales of Known space (1974), The Warlock (1984), World of PTVVS (1965), A World Out of Time (1975), Box: 15, Folder: 46. 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/230452 Accessed May 15, 2024.