Lupi, Silvia, Mauro Bergamini, Enrica Guidi, Pasquale Gregorio, and HPV Collaborative Group. 2014. “Cross-Sectional Seroprevalence of Antibodies Against 6, 11, 16 and 18 Human Papilloma Virus (HPV) Types Among Teenagers and Young Women in Italy”. Annali dell’Istituto Superiore Di Sanità 50 (2). Rome, IT:171-77. https://annali.iss.it/index.php/anna/article/view/46.