Cita APA (7a ed.)
Allen, W. L. National Geographic: Vol. 203, no. 1, January 2003. National Geographic Society.
Cita estilo Chicago (17a ed.)
Allen, William L. National Geographic: Vol. 203, No. 1, January 2003. Washington, EUA: National Geographic Society.
Cita MLA (9a ed.)
Allen, William L. National Geographic: Vol. 203, No. 1, January 2003. National Geographic Society.
警告：這些引文格式不一定是100％准確.