1. W. J. Morae and J. L. Cartter, Improvement in Soybeans. U. S. Dept. Agr. Year Book, 1937; 1154–1189, illus.
2. Piper and Morse, The Soybean. McGraw-Hill (1923).
3. Klare S. Markley and Warren H. Goss, The Chemistry and Technology of the Soybean and Its Derived Products (1942).