MAYAHI, M, M R SEIFYABAD SHAPOURI, and G. GOUMARAN DARABI. 2006. “Effect of Time Vaccination on Immunization of Broiler Chicks Against Influenza A Subtype H9 N2 Virus”. The Indian Journal of Animal Sciences 76 (1). https://doi.org/10.56093/ijans.v76i1.3489.