Não informado. (1956). Research for farmers. Department of Agriculture.
Chicago-referens (17:e uppl.)Não informado. Research for Farmers. Ottawa: Department of Agriculture, 1956.
MLA-referens (8:e uppl.)Não informado. Research for Farmers. Department of Agriculture, 1956.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.