Double Detective. New York, N.Y.: The Frank A. Munsey Company, November 1937

Double Detective. New York, N.Y.: The Frank A. Munsey Company, November 1937, Volume: Gilbert C153. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/525789 Accessed December 26, 2025.