Cita APA (7a ed.)

Kaplan, F. (2003). The singular Mark Twain: A biography. Doubleday.

Cita Chicago Style (17a ed.)

Kaplan, Fred. The Singular Mark Twain: A Biography. New York [etc.]: Doubleday, 2003.

Cita MLA (9a ed.)

Kaplan, Fred. The Singular Mark Twain: A Biography. Doubleday, 2003.