APA (7th ed.) Citation

National Geographic Society (U.S.). (1977). Visiting our past: A supplemental guide to selected sites. National Geographic Society.

Chicago Style (17th ed.) Citation

National Geographic Society (U.S.). Visiting Our Past: A Supplemental Guide to Selected Sites. Washington: National Geographic Society, 1977.

MLA (9th ed.) Citation

National Geographic Society (U.S.). Visiting Our Past: A Supplemental Guide to Selected Sites. National Geographic Society, 1977.