APA-viite (7. p.)
Graves, W. National Geographic: Vol. 178, no. 2, August 1990. National Geographic Society.
Chicago-viite (17. p.)
Graves, William. National Geographic: Vol. 178, No. 2, August 1990. Washington, EUA: National Geographic Society.
MLA-viite (9. p.)
Graves, William. National Geographic: Vol. 178, No. 2, August 1990. National Geographic Society.
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