Cita APA (7a ed.)
Allen, W. L. National Geographic: Vol. 207, no. 2, February 2005. National Geographic Society.
Cita estilo Chicago (17a ed.)
Allen, William L. National Geographic: Vol. 207, No. 2, February 2005. Washington, EUA: National Geographic Society.
Cita MLA (9a ed.)
Allen, William L. National Geographic: Vol. 207, No. 2, February 2005. National Geographic Society.
Precaución: Estas citas no son 100% exactas.