Zimmermann, E. W. (1951). World resources and industries: A functional appraisal of the availability of agticulture and industrial materials. New York: Happer and Brother Publisher.
Παραπομπή Chicago StyleZimmermann, Erich W. World Resources and Industries: A Functional Appraisal of the Availability of Agticulture and Industrial Materials. New York: Happer and Brother Publisher, 1951.
Παραπομπή MLAZimmermann, Erich W. World Resources and Industries: A Functional Appraisal of the Availability of Agticulture and Industrial Materials. New York: Happer and Brother Publisher, 1951.
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