Galaxy Science Fiction Novel No. 1. Sinister Barrier. New York: World Editions, Inc., 1950

Galaxy Science Fiction Novel No. 1. Sinister Barrier. New York: World Editions, Inc., 1950, Volume: Gilbert B253. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/526048 Accessed December 26, 2025.