McKenzie, G. D., & Utgard, R. O. Man and his physical environment: Readings in environmental geology.
Lua i Stíl Chicago (17ú heag.)McKenzie, Garry D., agus Russell O. Utgard. Man and His Physical Environment: Readings in Environmental Geology.
Lua MLA (9ú heag.)McKenzie, Garry D., agus Russell O. Utgard. Man and His Physical Environment: Readings in Environmental Geology.
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