MLA

Christopher, Frederick, and Loyal Davis. Christopher's Textbook of Surgery. 9th ed. Philadelphia, Pa: Saunders, 1968.

APA

Christopher, F., & Davis, L. (1968). Christopher's textbook of surgery. 9th ed. Philadelphia, Pa: Saunders.

Chicago

Christopher, Frederick, Christopher's Textbook of Surgery. Edited by Loyal Davis. 9th ed. Philadelphia, Pa: Saunders, 1968.