“Improvement of the Blood Characteristics of the Broiler Chickens by Addition Tryptophan Acid Supplement Levels in Ration”. Baghdad Science Journal 9, no. 1 (March 4, 2012): 45–49. Accessed May 6, 2024. https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/1331.