APA (7th ed.) Citation

Hancock, W. K. (1943). Empire in the changing world. Penguin Books.

Chicago Style (17th ed.) Citation

Hancock, W. K. Empire in the Changing World. New York: Penguin Books, 1943.

MLA (8th ed.) Citation

Hancock, W. K. Empire in the Changing World. Penguin Books, 1943.