Two Complete Detective Books. New York: Real Adventures Pub. Co., Inc., Winter 1939

Two Complete Detective Books. New York: Real Adventures Pub. Co., Inc., Winter 1939, Volume: Gilbert D1119. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/527880 Accessed December 27, 2025.