Cita APA (7a ed.)

Marden, O. S. (1907). The optimistic life. Marden, Orison Swett.

Cita Chicago Style (17a ed.)

Marden, Orison Swett. The Optimistic Life. New York: Marden, Orison Swett, 1907.

Cita MLA (9a ed.)

Marden, Orison Swett. The Optimistic Life. Marden, Orison Swett, 1907.