A. Bateman, Z. Liu, and D. A. R. Sr., “Bioefficacy Determination of Methionine Hydroxy Analog-Free Acid Relative to DL-Methionine in Laying Hen Diets with Limited Methionine Using Different Regression Models”, Int. J. Poult. Sci., vol. 4, no. 9, pp. 628–632, Aug. 2005, doi: 10.3923/ijps.2005.628.632.