APA (7th ed.) Citation

Joad, C. E. M. (1939). Why war? Penguin Books Limited.

Chicago Style (17th ed.) Citation

Joad, Cyril Edwin Mitchinson. Why War? Harmondsworth: Penguin Books Limited, 1939.

MLA (8th ed.) Citation

Joad, Cyril Edwin Mitchinson. Why War? Penguin Books Limited, 1939.