kadhim, L.I. et al. 2016. Histopathological changes of trachea in three genetic lines of broilers vaccinated with avian infectious bronchitis virus. Kufa Journal for Veterinary Medical Sciences. 7, 1B (Oct. 2016), 164–171. DOI:https://doi.org/10.36326/kjvs/2016/v7i1B4251.