Não informado. (1946). Iowa farm science. Iowa State University of Science and Technology, Cooperative Extension Service.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. Iowa Farm Science. Ames, Iowa: Iowa State University of Science and Technology, Cooperative Extension Service, 1946.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. Iowa Farm Science. Iowa State University of Science and Technology, Cooperative Extension Service, 1946.
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