Ehrlich, P. R. (1973). Human ecology: Problems and solutions. San Francisco: W. H. freeman.
Trích dẫn kiểu ChicagoEhrlich, Paul R. Human Ecology: Problems and Solutions. San Francisco: W. H. freeman, 1973.
Deismireacht MLAEhrlich, Paul R. Human Ecology: Problems and Solutions. San Francisco: W. H. freeman, 1973.
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