M. Yousefi and K. Karkoodi, “Effect of Probiotic Thepax® and Saccharomyces cerevisiae Supplementation on Performance and Egg Quality of Laying Hens”, Int. J. Poult. Sci., vol. 6, no. 1, pp. 52–54, Dec. 2006, doi: 10.3923/ijps.2007.52.54.