APA (7th ed.) Citation

Lewis, C. S. (1965). The problem of pain (6a imp.). Collins.

Chicago Style (17th ed.) Citation

Lewis, C. S. The Problem of Pain. 6a imp. London [etc.]: Collins, 1965.

MLA (9th ed.) Citation

Lewis, C. S. The Problem of Pain. 6a imp. Collins, 1965.

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