The measles outbreak in Bulgaria, 2009–2011: An epidemiological assessment and lessons learnt Muscat, Mark and Marinova, Lili and Mankertz, Annette and Gatcheva, Nina and Mihneva, Zafira and Santibanez, Sabine and Kunchev, Angel and Filipova, Radosveta and Kojouharova, Mira, Eurosurveillance, 21, 30152 (2016), https://doi.org/10.2807/1560-7917.ES.2016.21.9.30152