Não informado. (1962). Farm index. U.S. Department of Agriculture, Economic Research Service.
Chicago-referens (17:e uppl.)Não informado. Farm Index. Washington: U.S. Department of Agriculture, Economic Research Service, 1962.
MLA-referens (8:e uppl.)Não informado. Farm Index. U.S. Department of Agriculture, Economic Research Service, 1962.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.