RT Journal Article SR Electronic(1) A1 Eurosurveillance editorial team YR 2009 T1 Pandemic alert level 6: Scientific criteria for an influenza pandemic fulfilled* JF Eurosurveillance VO 14 IS 23 SP 19237 OP DO https://doi.org/10.2807/ese.14.23.19237-en UL https://www.eurosurveillance.org/content/10.2807/ese.14.23.19237-en