A. O. Abbas, A. A. El-Dein, A. Desoky, and M. A. Galal, “The Effects of Photoperiod Programs on Broiler Chicken Performance and Immune Response”, Int. J. Poult. Sci., vol. 7, no. 7, pp. 665–671, Jun. 2008, doi: 10.3923/ijps.2008.665.671.