Não informado. (1940). Agricultural Science and Genetics Newsletter. U.S. Department of Agriculture.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Agricultural Science and Genetics Newsletter. Cold Spring Harbor, NY: U.S. Department of Agriculture, 1940.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Agricultural Science and Genetics Newsletter. U.S. Department of Agriculture, 1940.
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