Freuler, Michael, Susan De Crom, Christoph Hatz, and Silja Bühler. “Varicella Seroprevalence in Individuals With a Negative or Unknown Varicella History – Results from a Large Travel Clinic in Switzerland Between 2008 and 2015”. Swiss Medical Weekly 146, no. 3536 (August 28, 2016): w14342. Accessed June 13, 2024. https://smw.ch/index.php/smw/article/view/2217.