Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

Ernst, Carl H., y Roger W. Barbour. Turtles of the World. Washington [etc.]: Smithsonian Institution Press, 1989.

Cita MLA (9a ed.)

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