Não informado. (2007). Report of the Division of the Agriculture. Iowa State College, Division of the Agriculture.
Chicago-referens (17:e uppl.)Não informado. Report of the Division of the Agriculture. Ames, Iowa: Iowa State College, Division of the Agriculture, 2007.
MLA-referens (8:e uppl.)Não informado. Report of the Division of the Agriculture. Iowa State College, Division of the Agriculture, 2007.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.