APA (7th ed.) Citation

Lewis, C. S. (1964). Letters to Malcolm: Chiefly on prayer. G. Bles.

Chicago Style (17th ed.) Citation

Lewis, C. S. Letters to Malcolm: Chiefly on Prayer. London: G. Bles, 1964.

MLA (8th ed.) Citation

Lewis, C. S. Letters to Malcolm: Chiefly on Prayer. G. Bles, 1964.