Chattopadhyay, K.; Mondal, M.; Roy, B. Comparative Efficacy of DL-Methionine and Herbal Methionine on Performance of Broiler Chicken. Int. J. Poult. Sci. 2006, 5 (11), 1034–1039. https://doi.org/10.3923/ijps.2006.1034.1039.