National Geographic Society (U.S.). Special Publications Division. (1989). Exploring your world: The adventure of geography. National Geographic Society.
Chicago-viite (17. p.)National Geographic Society (U.S.). Special Publications Division. Exploring Your World: The Adventure of Geography. Washington, D.C: National Geographic Society, 1989.
MLA-viite (9. p.)National Geographic Society (U.S.). Special Publications Division. Exploring Your World: The Adventure of Geography. National Geographic Society, 1989.
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