2Nicholson K G, Webster R G, Hay A J. Influenza in pigs and their role in the intermediate host[M]. London: Blackwell Science, 1998. 137-145.
3Pensaert M, Ottis K, Vandeputte J, et al. Evidence for the natural transmission of influenza A virus from wild ducks to swine and its potential importance for man[J]. Bull WHOm 1981, 59:75-78.
4Olsen C W, Carey S, Hinshaw L, et al. Virologic and serologic surveillance for human, swine and avian influenza virus infections among pigs in the north-central United States[J]. Arch Virol, 2000, 145 (7) : 1399-1419.
5Ito T, Couceiro J, Kelm S, et al. Molecular basis for the generation in pigs of influenza A virus with pandemic potential[J]. J Virol, 1998, 72:7367-7373.
6Li L S, Lin Y P. Evidence for interspecies transmission and reassortment of influenza A viruses in pigs in southern China[J]. Virology, 1994, 202:825.
7Brown I H, Ludwig S, Olsen C W, et al. Antigenic and genetic analyses of HINI influenza viruses from European pigs[J]. J Gen Virol, 1997, 78:553-562.
8Weis W, Brwn J H, Cusack S, et al. Structure of the influenza virus hemagglutinin complex with its receptorsialicacid[J]. Nature, 1988, 333:426-431.
9Kawaoka Y, Webster R G. Sequence requirements for cleavage activation of influenza virus hemagglutinin expressed in mammalian cells[J]. Pro Natl Acad Sci USA, 1988, 85:324-328.
10Wright S M, Kawaoka Y, Sharp G B, et al. Interspeeies transmission and reassortment of influenza viruses in pigs and turkeys in the United State[J]. Am J Epidemiol, 1992, 136(4);488-497.