9Rota P A,Wallis T R,Harmon M W,et al.Cocirculation of two distinct evolutionary lineages of influenza typeB virus since 1983[J].Virology,1990,175(1):592.
10Chi X S,Hu A,Bolar T V,et al.Detection and characterization of new influenza B virus variant s in 2002[J].J Clin Microbiol,2005,43(5):2345.