Do men who have sex with men use serosorting with casual partners in France? Results of a nationwide survey (ANRS-EN17-Presse Gay 2004) Velter, A and Bouyssou-Michel, A and Arnaud, A and Semaille, C, Eurosurveillance, 14, 19416 (2009), https://doi.org/10.2807/ese.14.47.19416-en