Cita APA (7th ed.)
Garrett, W. E. National Geographic: Vol. 160, no. 3, September 1981. National Geographic Society.
Cita Chicago (17th ed.)
Garrett, Wilbur E. National Geographic: Vol. 160, No. 3, September 1981. Washington, EUA: National Geographic Society.
Cita MLA (9th ed.)
Garrett, Wilbur E. National Geographic: Vol. 160, No. 3, September 1981. National Geographic Society.
Atenció: Aquestes cites poden no estar 100% correctes.