APA

Lewis C. S., . (1943). The screwtape letters. New York: The Macmillan Co.

Chicago

Lewis C S, . 1943. The screwtape letters. New York: The Macmillan Co.

Harvard

Lewis C. S., . (1943). The screwtape letters. New York: The Macmillan Co.

MLA

Lewis C S, . The screwtape letters. New York: The Macmillan Co. 1943.