APA (7th ed.) Citation

Smith, C. A. (1916). O. Henry biography. Doubleday, Page.

Chicago Style (17th ed.) Citation

Smith, C. Alphonso. O. Henry Biography. Garden City, N.Y.: Doubleday, Page, 1916.

MLA (8th ed.) Citation

Smith, C. Alphonso. O. Henry Biography. Doubleday, Page, 1916.