مردانی,ک , and Alimehr,M . "Molecular analysis of the S1 gene of vaccine strains of infectious bronchitis virus using reverse transcriptase-polymerase chain reaction and restriction fragment length polymorphism" .e20868 , Iranian Journal of Veterinary Medicine, 4, 1, 2010, e20868. doi: 10.22059/ijvm.2010.20868