Roberson, K.D., et al. “Effect of Corn Distiller`s Dried Grains With Solubles at Various Levels on Performance of Laying Hens and Egg Yolk Color”. International Journal of Poultry Science, vol. 4, no. 2, Jan. 2005, pp. 44–51, https://doi.org/10.3923/ijps.2005.44.51.