APA (7th ed.) Citation

Lewis, C. (1952). Mere christianity. Collier Books.

Chicago Style (17th ed.) Citation

Lewis, C.S. Mere Christianity. New York: Collier Books, 1952.

MLA (9th ed.) Citation

Lewis, C.S. Mere Christianity. Collier Books, 1952.

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