1. Proteins and Amino Acids in Animal Nutrition;Almquist,1972
2. Bird, H. R., D. R. Clandinin, J. R. Couch, H. M. Edwards, Jr., F. W. Hill, James McGinnis, E. C. Naber, Subcommittee on Poultry Nutrition, 1971. Nutrient Requirements of Poultry, Sixth Revised Edition, Number 1.
3. Combs, G. F., 1970, Maryland broiler nutrition studies. Proceedings, Maryland Nutrition Conference: 81-89.
4. Combs, G. F., 1963, Maryland broiler nutrition studies. Proceedings, Maryland Nutrition Conference: 48-72.
5. Combs, G. F., 1961, Maryland broiler nutrition studies. Proceedings, Maryland Nutrition Conference: 51-64.