1. AOAC, 1995. Official Methods of Analysis, 16th ed. Association of Official Analytical Chemists, Arlington, VA.
2. Microflora of microorganisms and several characteristics of laban, a traditional natural fermented milk in Yemen;Arai;Milk Sci. (Japan),2002
3. The utilization of acetic, propionic and butyric acids in fasting sheep;Armstrong;Br. J. Nutr.,1957
4. Blaxter, K.L., 1980. Feeds as sources of energy for ruminant animals. The Massey-Ferguson Papers. Massey Ferguson Ltd., Coventry.
5. Brouwer, E., 1965. Report of Sub-committee on Constants and Factors. In: Blaxter, K.L. (Ed.), Proceedings of the Third EAAP Symposium on Energy Metabolism, Troon, Scotland, 11, 441–443.