1. Code of Federal Regulations., 1977 . Title 21, Food and Drugs part 100-199 ; 155.200 and 172.135 Revised as of April 1.
2. H.W. Crittenden, L.V. Svec, and E.L. Wisk, 1975 . The Emerald Soybean . University of Delaware Agricultural Experiment Station Circular14 , Newark, DE.