Official Crossword Puzzles. New York: Dell Publishing Co., Inc., 1940

Official Crossword Puzzles. New York: Dell Publishing Co., Inc., 1940, Volume: Gilbert D727. Robert L. Gilbert First Issues collection, Gilbert. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/526909 Accessed December 27, 2025.