APA (7th ed.) Citation

Lewis, C. S., & Lewis, W. H. (1966). Letters ([1st American ed.].). Harcourt, Brace & World.

Chicago Style (17th ed.) Citation

Lewis, C. S., and W. H. Lewis. Letters. [1st American ed.]. New York: Harcourt, Brace & World, 1966.

MLA (8th ed.) Citation

Lewis, C. S., and W. H. Lewis. Letters. [1st American ed.]. Harcourt, Brace & World, 1966.