RT Journal Article SR Electronic(1) A1 ECDC Technical Emergency Team YR 2009 T1 Initial epidemiological findings in the European Union following the declaration of pandemic alert level 5 due to influenza A (H1N1) JF Eurosurveillance VO 14 IS 18 SP 19204 OP DO https://doi.org/10.2807/ese.14.18.19204-en UL https://www.eurosurveillance.org/content/10.2807/ese.14.18.19204-en