1. Austin, R. B., J. Bingham, R. D. Blackwell, L. T. Evans, M. A. Ford, C. L. Morgan, and M. Taylor. 1980. Genetic improvements in winter wheat yields since 1900 and associated physiological changes. J. Agric. Sci. (Cambridge) 94: 675–689.
2. Bernard, R. L., and J. G. Shannon. 1980. Registration of Franklin soybean. Crop Sci. 20: 825.
3. Blaine, M. R. 1979. The Ioway Indians. Univ. Oklahoma Press, Norman, OK.
4. Briggle, L. W., S. L. Strauss, D. E. Hamilton, and G. H. Howse. 1982. Distribution of the varieties and classes of wheat in the United States in 1979. USDA-ARS Statistical Bulletin No. 676, Washington, DC.
5. Crop Reporting Board, Economics and Statistics Service, USDA. 1980. Soybeans: regional distribution of major varieties.In Crop Production, November, 1980. Crop Reporting Board, ESS, USDA, Washington, DC.