APA (7th ed.) Citation

(1929). Signal communication: Dropped and pick-up airplane messages. GPO.

Chicago Style (17th ed.) Citation

Signal Communication: Dropped and Pick-up Airplane Messages. [Washington]: GPO, 1929.

MLA (9th ed.) Citation

Signal Communication: Dropped and Pick-up Airplane Messages. GPO, 1929.

Warning: These citations may not always be 100% accurate.