Cita APA (7th ed.)

Schullery, P. (2001). America's national parks: The spectacular forces that shaped our treasured lands (1a. ed.). Discovery Channel.

Cita Chicago (17th ed.)

Schullery, Paul. America's National Parks: The Spectacular Forces That Shaped Our Treasured Lands. 1a. ed. Nueva York: Discovery Channel, 2001.

Cita MLA (9th ed.)

Schullery, Paul. America's National Parks: The Spectacular Forces That Shaped Our Treasured Lands. 1a. ed. Discovery Channel, 2001.