Hadwiger, Donald F.; Kihl, Young; Sapp, Stephen G.; Green, John R.; Hayes, Dermot J.; Williams, Gary W.; Gong, Shang-Chi; Knipe, C. Lynn; Wong, John; Khan, Linda; Seim, Emerson L.

Midwest Agribusiness Trade Research and Information Center, Iowa State University, Des Moines, Iowa, and Ames, Iowa, (1989)