Susanna K. P. Lau,Paul Lee,Alan K. L. Tsang, Cyril C. Y. Yip,Herman Tse,Rodney A. Lee, Lok-Yee So,et al:Molecular Epidemiology of Human Coronavirus OC43 Reveals Evolution of Different Genotypes over Time and Recent Emer- gence of a Novel Genotype due to Natural Rec-ombination,J Virol,85,11325-11337(2011) .