4Burk RD. Sexual behavior and partner characteristics are the predominant risk factors for genital human papillomavirus infection in young women[J]. J infect disease, 1996,174(4):679-689.
5Kataja V, Syrjanen S,Yliskoski M,et al.Risk factors associated with cervical human papillomavirus infections: a case-control study[J]. Am J Epidemiology, 1993,138(7):735-745.