Trích dẫn APA

Eckholm, E. P. (1982). Down to earth: Environment and human needs. Affiliated East-West Press.

Trích dẫn kiểu Chicago

Eckholm, Erik P. Down to Earth: Environment and Human Needs. New Delhi: Affiliated East-West Press, 1982.

Trích dẫn MLA

Eckholm, Erik P. Down to Earth: Environment and Human Needs. Affiliated East-West Press, 1982.

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