Não informado. (1959). World agricultural economics and rural sociology abstracts. Commonwealth Agricultural Bureau.
Chicago-referens (17:e uppl.)Não informado. World Agricultural Economics and Rural Sociology Abstracts. Farnham Royal, Inglaterra: Commonwealth Agricultural Bureau, 1959.
MLA-referens (8:e uppl.)Não informado. World Agricultural Economics and Rural Sociology Abstracts. Commonwealth Agricultural Bureau, 1959.
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