Yersinia enterocolitica O:9 infections associated with bagged salad mix in Norway, February to April 2011 MacDonald, E and Heier, B T and Stalheim, T and Cudjoe, K S and Skjerdal, T and Wester, A and Lindstedt, B A and Vold, L, Eurosurveillance, 16, 19866 (2011), https://doi.org/10.2807/ese.16.19.19866-en