Gupta, S. C., P. C. Sawhney, and N. D. Kehar. “Maintenance Protein Requirements of Hill Cattle As Determined from Nitrogen Balance Data”. The Indian Journal of Nutrition and Dietetics, vol. 7, no. 1, Jan. 1971, pp. 36-43, https://www.informaticsjournals.com/index.php/ijnd/article/view/11173.