8Fu Y,Pan M,Wang X,et al.Molecular detection and typing of duck hepatitis A virus directly from clinical specimens[J].Vet Microbiol,2008,131:247-257.
9Jonassen C M,Kofstad T,Larsen I,et al.Molecular identification and characterization of novel coronaviruses infecting graylag geese (Anser anser),feral pigeons (Columbia livia) and mallards (Anas platyrhynchos)[J].J Gen Virol,2005,86:1597-1607.
10Thompson J D,Higgins D G,Gibson T J.Clustal W:improving the sensitivity of progressive multiple sequence alignment through sequence weighting,position-specific gap penalties and weight matrix choice[J].Nucleic Acid Res,1994,22:4673-4680.
