APA (7th ed.) Citation

Keegan, J. (1990). The Second World War / John Keegan. Penguin Books.

Chicago Style (17th ed.) Citation

Keegan, John. The Second World War / John Keegan. New York: Penguin Books, 1990.

MLA (9th ed.) Citation

Keegan, John. The Second World War / John Keegan. Penguin Books, 1990.

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