Seasonality and geographical spread of respiratory syncytial virus epidemics in 15 European countries, 2010 to 2016 Broberg, Eeva K and Waris, Matti and Johansen, Kari and Snacken, René and Penttinen, Pasi and European Influenza Surveillance Network, Eurosurveillance, 23, 17-00284 (2018), https://doi.org/10.2807/1560-7917.ES.2018.23.5.17-00284