Cita APA (7a ed.)
Grosvenor, M. B. (1971). National geographic: December 1971. National Geographic Society.
Cita estilo Chicago (17a ed.)
Grosvenor, Melville Bell. National Geographic: December 1971. Washington, EUA: National Geographic Society, 1971.
Cita MLA (9a ed.)
Grosvenor, Melville Bell. National Geographic: December 1971. National Geographic Society, 1971.
Precaución: Estas citas no son 100% exactas.