National Geographic Society (U.S.) Special Publications Division. (1979). Mysteries of the ancient world. The Society.
Chicago-referens (17:e uppl.)National Geographic Society (U.S.) Special Publications Division. Mysteries of the Ancient World. Washington: The Society, 1979.
MLA-referens (9:e uppl.)National Geographic Society (U.S.) Special Publications Division. Mysteries of the Ancient World. The Society, 1979.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.