APA (7th ed.) Zitazioa
Graves, W. National Geographic: Vol. 186, no. 1, July 1994. National Geographic Society.
Chicago Style (17th ed.) Zitazioa
Graves, William. National Geographic: Vol. 186, No. 1, July 1994. Washington, EUA: National Geographic Society.
MLA (9th ed.) Zitazioa
Graves, William. National Geographic: Vol. 186, No. 1, July 1994. National Geographic Society.
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