APA (7th ed.) Citation

National Geographic Society. (1978). The heart of the Grand Canyon: / Grand Canyon Park, Arizona. National Geographic Magazine.

Chicago Style (17th ed.) Citation

National Geographic Society. The Heart of the Grand Canyon: / Grand Canyon Park, Arizona. Washigton, Estados Unidos: National Geographic Magazine, 1978.

MLA (9th ed.) Citation

National Geographic Society. The Heart of the Grand Canyon: / Grand Canyon Park, Arizona. National Geographic Magazine, 1978.