1. Berek JS, editor. Berek and Novak’s gynecology. 14th ed. Stanford: Lippincott Williams & Wilkins; 2007.
2. Walboomers JMJ, Manos MM. Human papillomavirus is a necessary cause of invasive cervical cancer worldwide. J Pathol. 1999;189:12–9.
3. WHO. Comprehensive cervical cancer prevention and control: a healthier future for girls and women. Geneva, Switzerland; 2013.
4. Ferlay JS, Bray F, Forman D, Mathers C. GLOBOCAN 2008: cancer Incidence and Mortality Worldwide in 2008. Lyon, France: International Agency for Research on Cancer. 2010; 2013. Available from: http://globocan.iarc.f .
5. Castellsagué XS, Aguado T, Louie KS, Bruni L, Muñoz J, et al. HPV and Cervical Cancer in the World: WHO/ICO Information Centre on HPV and Cervical Cancer (HPV Information Centre); 2007.