Did public health travel advice reach EURO 2012 football fans? A social network survey Janiec, J and Zielicka-Hardy, A and Polkowska, A and Rogalska, J and Sadkowska-Todys, M, Eurosurveillance, 17, 20238 (2012), https://doi.org/10.2807/ese.17.31.20238-en