APA (7th ed.) Citation

John, E. (1964). The Popes: A concise biographical history (1st ed.].). Hawthorn Books.

Chicago Style (17th ed.) Citation

John, Eric. The Popes: A Concise Biographical History. 1st ed.]. New York: Hawthorn Books, 1964.

MLA (9th ed.) Citation

John, Eric. The Popes: A Concise Biographical History. 1st ed.]. Hawthorn Books, 1964.