1. World Health Organization (WHO). WHO discussion papers on adolescence. Issues in Adolescent Health and Development: Contraception. Geneva. 2004. Available at: http://whqlibdoc.who.int/publications/2004/9241591447_eng.pdf . Accessed March 2, 2015.
2. Clark T, Fleming T, Bullen P, et al. Health and well-being of secondary school students in New Zealand: trends between 2001, 2007 and 2012. J Paediatr Child Health. 2013; 49(11): 925–34. doi: 10.1111/jpc.12427 .
3. Kann L, Lowry R, Eaton D, Wechsler H. Trends in HIV-related risk behaviors among high school students—United States, 1991–2011. Morb Mortal Wkly Rep. 2012; 61(29): 556–60.
4. Moreno A, Rodríguez E. Informe de la juventud en España 2012. Madrid: Instituto de la Juventud (INJUVE). Gobierno de España. Observatorio de la Juventud en España; 2012.
5. Holmes KK, Levine R, Weaver M. Effectiveness of condoms in preventing sexually transmitted infections. Bull World Health Organ. 2004; 82(6): 454–61.