RT Journal Article SR Electronic(1) A1 Ånestad, G A1 Nordbø, S A YR 2009 T1 Interference between outbreaks of respiratory viruses JF Eurosurveillance VO 14 IS 41 SP 19359 OP DO https://doi.org/10.2807/ese.14.41.19359-en UL https://www.eurosurveillance.org/content/10.2807/ese.14.41.19359-en