Space World; The News Magazine of Astro-Science. New York: Spaceways, Inc., April 1961

Space World; The News Magazine of Astro-Science. New York: Spaceways, Inc., April 1961, Volume: Gilbert D967. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/527538 Accessed December 27, 2025.