Não informado. (1975). Agricultural Outlook. U.S. Department of Agriculture, Economic Research Service.
Chicago-referens (17:e uppl.)Não informado. Agricultural Outlook. Washington: U.S. Department of Agriculture, Economic Research Service, 1975.
MLA-referens (8:e uppl.)Não informado. Agricultural Outlook. U.S. Department of Agriculture, Economic Research Service, 1975.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.