Cita APA (7a ed.)

Ditmars, R. L. (1931). Snakes of the world. The Macmillan.

Cita Chicago Style (17a ed.)

Ditmars, Raymond L. Snakes of the World. New York: The Macmillan, 1931.

Cita MLA (9a ed.)

Ditmars, Raymond L. Snakes of the World. The Macmillan, 1931.