Cita APA (7th ed.)
Grosvenor, G. M. National geographic: October 1975. National Geographic Society.
Cita Chicago (17th ed.)
Grosvenor, Gilbert M. National Geographic: October 1975. Washington, EUA: National Geographic Society.
Cita MLA (9th ed.)
Grosvenor, Gilbert M. National Geographic: October 1975. National Geographic Society.
Atenció: Aquestes cites poden no estar 100% correctes.