Cita APA

National Geographic Society. (1999). The complete National Geographic: 110 years of National Geographic magazine on CD-ROM. National Geographic Society.

Citación estilo Chicago

National Geographic Society. The Complete National Geographic: 110 Years of National Geographic Magazine on CD-ROM. Washington, D.C: National Geographic Society, 1999.

Cita MLA

National Geographic Society. The Complete National Geographic: 110 Years of National Geographic Magazine on CD-ROM. National Geographic Society, 1999.