Não informado. (1920). Milk Industry. National Dairymen's Association.
Chicago-referens (17:e uppl.)Não informado. Milk Industry. London: National Dairymen's Association, 1920.
MLA-referens (8:e uppl.)Não informado. Milk Industry. National Dairymen's Association, 1920.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.