APA (7th ed.) Citation

Gardner, J. (1939). War in the air: R.A.F. Penguin Books.

Chicago Style (17th ed.) Citation

Gardner, James. War in the Air: R.A.F. Harmondsworth: Penguin Books, 1939.

MLA (9th ed.) Citation

Gardner, James. War in the Air: R.A.F. Penguin Books, 1939.