Iowa State University. Cooperative Extension Service. Dairy Husbandry and Dairy Products Extension Service publications and records.
Chicago-referens (17:e uppl.)Iowa State University. Cooperative Extension Service. Dairy Husbandry and Dairy Products Extension Service Publications and Records.
MLA-referens (8:e uppl.)Iowa State University. Cooperative Extension Service. Dairy Husbandry and Dairy Products Extension Service Publications and Records.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.