C. Bunchasak and T. Silapasorn, “Effects of Adding Methionine in Low-Protein Diet on Production Performance, Reproductive Organs and Chemical Liver Composition of Laying Hens under Tropical Conditions”, Int. J. Poult. Sci., vol. 4, no. 5, pp. 301–308, Apr. 2005, doi: 10.3923/ijps.2005.301.308.