Citazione Stile APA (7a Edizione)

National Geographic Society. (2015). Answer book: 10,001 fast facts about our world. National Geographic Society.

Citazione stile Chigago Style (17a edizione)

National Geographic Society. Answer Book: 10,001 Fast Facts About Our World. Washington, D.C.: National Geographic Society, 2015.

Citatione MLA (9a ed.)

National Geographic Society. Answer Book: 10,001 Fast Facts About Our World. National Geographic Society, 2015.