Detection of human norovirus from frozen raspberries in a cluster of gastroenteritis outbreaks Maunula, L and Roivainen, M and Keränen, M and Mäkelä, S and Söderberg, K and Summa, M and von Bonsdorff, C H and Lappalainen, M and Korhonen, T and Kuusi, M and Niskanen, T, Eurosurveillance, 14, 19435 (2009), https://doi.org/10.2807/ese.14.49.19435-en