APA

University Illinois, . (1991). Bulletin : Univ. Illinois at Urbana-Champaign Coll. of Agric. Exp. Station. Illinois: University Illinois.

Chicago

University Illinois, . 1991. Bulletin : Univ. Illinois at Urbana-Champaign Coll. of Agric. Exp. Station. Illinois: University Illinois.

Harvard

University Illinois, . (1991). Bulletin : Univ. Illinois at Urbana-Champaign Coll. of Agric. Exp. Station. Illinois: University Illinois.

MLA

University Illinois, . Bulletin : Univ. Illinois at Urbana-Champaign Coll. of Agric. Exp. Station. Illinois: University Illinois. 1991.