APA (7th ed.) Citation

Stebbing, L. S. (1939). Thinking to some purpose. Penguin Books.

Chicago Style (17th ed.) Citation

Stebbing, L. Susan. Thinking to Some Purpose. Harmondsworth: Penguin Books, 1939.

MLA (8th ed.) Citation

Stebbing, L. Susan. Thinking to Some Purpose. Penguin Books, 1939.