National Geographic Socity. Special Publication Division & Gray, W. B. (1978). Power of nature. Prepared by the Special Publication Division, National Geographic Society.
Čikaški stil citiranja (17. izdanje)National Geographic Socity. Special Publication Division i William B. Gray. Power of Nature. Washington, DC: Prepared by the Special Publication Division, National Geographic Society, 1978.
MLA način citiranja (9. izdanje)National Geographic Socity. Special Publication Division i William B. Gray. Power of Nature. Prepared by the Special Publication Division, National Geographic Society, 1978.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.