Não informado. (2021). Illinois Bulletin. University of Illinois at Urbana-Champaign, Agricultural Experiment Station.
Chicago-referens (17:e uppl.)Não informado. Illinois Bulletin. Urbana, Ill: University of Illinois at Urbana-Champaign, Agricultural Experiment Station, 2021.
MLA-referens (8:e uppl.)Não informado. Illinois Bulletin. University of Illinois at Urbana-Champaign, Agricultural Experiment Station, 2021.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.