Cita APA

Marshak, S., & Prothero, D. R. (2001). Earth: Portrait of a planet. New York: Norton.

Citación estilo Chicago

Marshak, Stephen, y Donald R. Prothero. Earth: Portrait of a Planet. New York: Norton, 2001.

Cita MLA

Marshak, Stephen, y Donald R. Prothero. Earth: Portrait of a Planet. New York: Norton, 2001.