APA
United States D. o. t. I. N. P. S., . (1953). Talks. : Department of the Interior National Park Service.
Chicago
United States Department of the Interior National Park Service, . 1953. Talks. : Department of the Interior National Park Service.
Harvard
United States D. o. t. I. N. P. S., . (1953). Talks. : Department of the Interior National Park Service.
MLA
United States Department of the Interior National Park Service, . Talks. : Department of the Interior National Park Service. 1953.
