Cita APA (7th ed.)

-. (1989). Nature's wonderlands: National park of the world. National geography society.

Cita Chicago (17th ed.)

-. Nature's Wonderlands: National Park of the World. Washington: National geography society, 1989.

Cita MLA (9th ed.)

-. Nature's Wonderlands: National Park of the World. National geography society, 1989.