9Fraser C, Donnelly C A, Cauchemez S, et al. Pandemic potenitial of a strain of influenza A (H1N1) : Early Findings [J]. Science, 2009, 324 (5934): 1557-1561.
10Fraser C,Donnelly CA,Cauchemez S,et al.Pandemic potenitial of a strain of influenza A(H1N1):early findings[J].Science,2009,324(5934):1557-1561.