Initial surveillance of 2009 influenza A(H1N1) pandemic in the European Union and European Economic Area, April – September 2009
Devaux, I and Kreidl, P and Penttinen, P and Salminen, M and Zucs, P and Ammon, A and on behalf of the ECDC influenza surveillance group, Collective and and the national coordinators for influenza surveillance, Collective, Eurosurveillance, 15, 19740 (2010), https://doi.org/10.2807/ese.15.49.19740-en