RT Journal Article SR Electronic(1) A1 Mak, G C A1 Leung, C K A1 Cheng, K C A1 Wong, K Y A1 Lim, W YR 2011 T1 Evolution of the haemagglutinin gene of the influenza A(H1N1)2009 virus isolated in Hong Kong, 2009–2011 JF Eurosurveillance VO 16 IS 9 SP 19807 OP DO https://doi.org/10.2807/ese.16.09.19807-en UL https://www.eurosurveillance.org/content/10.2807/ese.16.09.19807-en