Cita APA (7th ed.)
Graves, W. (1994). National geographic: March 1994. National Geographic Society.
Cita Chicago (17th ed.)
Graves, William. National Geographic: March 1994. Washington, EUA: National Geographic Society, 1994.
Cita MLA (9th ed.)
Graves, William. National Geographic: March 1994. National Geographic Society, 1994.
Atenció: Aquestes cites poden no estar 100% correctes.