Não informado. (2007). Report of the Division of the Agriculture. Iowa State College, Division of the Agriculture.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Report of the Division of the Agriculture. Ames, Iowa: Iowa State College, Division of the Agriculture, 2007.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Report of the Division of the Agriculture. Iowa State College, Division of the Agriculture, 2007.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.