Khatun, A., S. D. Chowdhury, B. C. Roy, F. Sultana, P. Krishnan, and G. Channarayapatna. “Effect of Increasing Levels of Dietary Tryptophan on Growth Performance, Meat Yields and Cost Benefit of Commercial Broiler Chickens”. Journal of the Bangladesh Agricultural University, vol. 18, no. 1, Mar. 2020, pp. 124-30, https://banglajol.info/index.php/JBAU/article/view/73491.