Cita APA

Estados Unidos. Departament of the Interior. (1972). Part two of the national park system plan natural history. Washington, D.C.: [s.n.].

Citación estilo Chicago

Estados Unidos. Departament of the Interior. Part Two of the National Park System Plan Natural History. Washington, D.C.: [s.n.], 1972.

Cita MLA

Estados Unidos. Departament of the Interior. Part Two of the National Park System Plan Natural History. Washington, D.C.: [s.n.], 1972.