Nosocomial measles cluster in Denmark following an imported case, December 2008-January 2009 
Groth, C and Böttiger, B E and Plesner, A and Christiansen, A H and Glismann, S and Hogh, B, Eurosurveillance, 14, 19126 (2009), https://doi.org/10.2807/ese.14.08.19126-en