APA (7th ed.) Citation

Masters, E. L. (1938). Mark Twain: A portrait. Biblio and Tannen.

Chicago Style (17th ed.) Citation

Masters, Edgar Lee. Mark Twain: A Portrait. New York: Biblio and Tannen, 1938.

MLA (9th ed.) Citation

Masters, Edgar Lee. Mark Twain: A Portrait. Biblio and Tannen, 1938.