Não informado. Production Research Report. U.S. Department of Agriculture.
Chicago-referens (17:e uppl.)Não informado. Production Research Report. Washington: U.S. Department of Agriculture.
MLA-referens (8:e uppl.)Não informado. Production Research Report. U.S. Department of Agriculture.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.