APA (7th ed.) Citation

Johnson, P. (1980). A History of Christianity. Penguin.

Chicago Style (17th ed.) Citation

Johnson, Paul. A History of Christianity. Harmondsworth (England): Penguin, 1980.

MLA (9th ed.) Citation

Johnson, Paul. A History of Christianity. Penguin, 1980.

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