1. Introduction of soybean to North America by Samuel Bowen in 1765
2. Carpenter, K. J.Protein and EnergyA Study of Changing Ideas in Nutrition; Cambridge University Press: Cambridge, U.K., 1994; p 170.
3. Smith, A. K.; Circle, S. J.Soybean: Chemistry and Technology; Avi: Westport, CT, 1972.
4. American Soybean Association, St. Louis, MO, 2000, private communication.
5. Biological Nitrogen Fixation