APA (7th ed.) Citation

Lewis, C. S., & Sampson, A. (1941). The Problem of pain. Centenary press.

Chicago Style (17th ed.) Citation

Lewis, C. S., and Ashley Sampson. The Problem of Pain. London: Centenary press, 1941.

MLA (9th ed.) Citation

Lewis, C. S., and Ashley Sampson. The Problem of Pain. Centenary press, 1941.

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