3Cox NJ,Subbarao K. Influenza [ J ]. Lancet,1999,354 (9186): 1277-1282.
4Shaw MW,Xu X,Li Y,et al. Reappearance and global of variants of influenza B/Victoria/2/87 Lineage viruses in the 2000-2001 and 2001 -2002 seasons[ J]. Virology,2002,303(1) :1-8.