Não informado. (1940). Agricultural Science and Genetics Newsletter. U.S. Department of Agriculture.
Chicago-referens (17:e uppl.)Não informado. Agricultural Science and Genetics Newsletter. Cold Spring Harbor, NY: U.S. Department of Agriculture, 1940.
MLA-referens (8:e uppl.)Não informado. Agricultural Science and Genetics Newsletter. U.S. Department of Agriculture, 1940.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.