Dass, R. S., J. Kishan, and U. B. Singh. “Effect of Feeding Urea (Ammonia) Treated Paddy Straw on Rumen Metabolism in Cross-Bred Cattle”. The Indian Journal of Nutrition and Dietetics, vol. 21, no. 9, Sept. 1984, pp. 342-9, http://www.informaticsjournals.com/index.php/ijnd/article/view/11099.