1. Human papillomavirus-related disease in men: not just a women's issue;J.M. Palefsky;The Journal of adolescent health: official publication of the Society for Adolescent Medicine,2010
2. World Health Organization: International Agency for Research on Cancer (2019). Africa https://gco.iarc.fr/today/data/factsheets/populations/903-africa-fact-sheets.pdf.
3. Human papillomavirus (HPV) vaccine coverage achievements in low and middle-income countries 2007–2016;K.E. Gallagher;Papillomavirus Research,2017
4. Merck, Merck's investigational 9-valent HPV vaccine, V503, prevented 97 percent of cervical, vaginal and vulvar pre-cancers caused by five additional HPV types, in: Merck (Ed.), Phase III Study, Merck, USA, 2013.
5. Four year efficacy of prophylactic human papillomavirus quadrivalent vaccine against low grade cervical, vulvar, and vaginal intraepithelial neoplasia and anogenital warts: randomised controlled trial;J. Dillner;BMJ (Clin. Res. Ed.),2010