Não informado. (1959). Illinois research. University of Illinois at Urbana-Champaign, Agricultural Experiment Station.
Chicago-referens (17:e uppl.)Não informado. Illinois Research. Urbana, Ill: University of Illinois at Urbana-Champaign, Agricultural Experiment Station, 1959.
MLA-referens (8:e uppl.)Não informado. Illinois Research. University of Illinois at Urbana-Champaign, Agricultural Experiment Station, 1959.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.