Ghafoor, A. et al. 2005. Immunomodulatory Effects of Multistrain Probiotics (Protexin™) on Broiler Chicken Vaccinated Against Avian Influenza Virus (H9). International Journal of Poultry Science. 4, 10 (Sep. 2005), 777–780. DOI:https://doi.org/10.3923/ijps.2005.777.780.