1. Achacoso, A. S. Lignin and Its Relation to Other Chemical Constituents in Sudan and Millet Forages at Different Stages of Growth and Rates of Nitrogen Fertilization. M.S. thesis, Louisiana State University, Baton Rouge, Louisiana. 1959.
2. Association of Official Agricultural Chemists. Official Methods of Analysis. 7th ed. Washington, D. C. 1950.
3. Personal communication;Austin,1960
4. Corley, E L. A Study of Persistency of Lactation in Dairy Cattle. Ph.D. thesis, University of Wisconsin, Madison, Wisconsin. 1956.
5. Multiple Range and Multiple F-Tests;Duncan;Biometrics,1955