The natural history of human papillomavirus infection and cervical intraepithelial neoplasia among young women in the Guanacaste cohort study after initiation of sexual life. - Rodriguez AC; Burk R; Herrero R; Hildesheim A; Bratti C; Sherman ME; Solomon D; Guillen D; Alfaro M; Viscidi R; Morales J; Hutchinson M; et al. (Sexually Transmitted Diseases, 2007)