RT Journal Article SR Electronic T1 Review: vaccines against human papillomavirus prevent cervical cancer precursors in young women for at least 3 years JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 168 OP 168 DO 10.1136/ebm.12.6.168 VO 12 IS 6 YR 2007 UL http://ebm.bmj.com/content/12/6/168.abstract AB