Citazione Stile APA (7a Edizione)

Heacox, K. (2016). National Geographic the national parks: An illustrated history. National Geographic.

Citazione stile Chigago Style (17a edizione)

Heacox, Kim. National Geographic the National Parks: An Illustrated History. Washington, D.C: National Geographic, 2016.

Citatione MLA (9a ed.)

Heacox, Kim. National Geographic the National Parks: An Illustrated History. National Geographic, 2016.