Cita APA

Ernst, C. H., & Barbour, R. W. (1989). Turtles of the world. Washington, D.C.: Smithsonian Institution Press.

Citación estilo Chicago

Ernst, Carl H., y Roger W. Barbour. Turtles of the World. Washington, D.C.: Smithsonian Institution Press, 1989.

Cita MLA

Ernst, Carl H., y Roger W. Barbour. Turtles of the World. Washington, D.C.: Smithsonian Institution Press, 1989.