Cita APA (7a ed.)
Robert B. Keiter. To Conserve Unimpaired: The Evolution of the National Park Idea. Island Press.
Cita estilo Chicago (17a ed.)
Robert B. Keiter. To Conserve Unimpaired: The Evolution of the National Park Idea. Washington, EUA: Island Press.
Cita MLA (9a ed.)
Robert B. Keiter. To Conserve Unimpaired: The Evolution of the National Park Idea. Island Press.
Precaución: Estas citas no son 100% exactas.