Niven - Ringworld (1981), World of PTAVVS (n[o] d[ate]), Ringworld Engineers (1976), The Schumann Computer (1978), The Shape of Space (1968), Bordered in Black (1968), Box: 15, Folder: 44. 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/230450 Accessed May 16, 2024.