Rahimi S, Salehifar E, Ghorashi SA, Grimes JL, Torshizi MAK. The Effect of Egg-Derived Antibody on Prevention of Avian Influenza Subtype H9N2 in Layer Chicken. Int. J. Poult. Sci. 2007;6(3):207–210. doi:10.3923/ijps.2007.207.210