Genetic Evolution Characteristics of Genotype G57 Virus, A Dominant Genotype of H9N2 Avian Influenza Virus oleh Jinfeng Wang, Xuanjiang Jin, Jingkai Hu, Yifan Wu, Mengmeng Zhang, Xiao Li, Jianglin Chen, Shumin Xie, Jing Liu, Wenbao Qi, Wenbao Qi, Wenbao Qi, Wenbao Qi, Wenbao Qi, Ming Liao, Ming Liao, Ming Liao, Ming Liao, Ming Liao, Weixin Jia, Weixin Jia, Weixin Jia, Weixin Jia, Weixin Jia