1. Official methods of analysis;AOAC,1970
2. The nutrient requirements of farm livestock. No. 2, Ruminants;ARC,1965
3. Amount and physical form of feed and milk secretion in the cow;Armstrong,1968
4. The utilization of grass by ruminants;Blaxter,1964
5. The estimation of methane production by cattle;Bratzler;J. Nutrition,1940