Cita APA (7a ed.)

National Geographic Society. National Geographic Maps & National Geographic Maps. (1998). Millennium in maps: Population. National Geographic Society.

Cita Chicago Style (17a ed.)

National Geographic Society. National Geographic Maps y National Geographic Maps. Millennium in Maps: Population. Washington, D.C.: National Geographic Society, 1998.

Cita MLA (8a ed.)

National Geographic Society. National Geographic Maps y National Geographic Maps. Millennium in Maps: Population. National Geographic Society, 1998.