1. UNESCO (2009) International technical guidance on sexuality education. Volume I & II. Paris. http://unesdoc.unesco.org/images/0018/001832/183281e.pdf
2. Kivela J, Baltussen R, Ketting E (2011) Cost and cost-effectiveness analysis of school-based sexuality education programmes in six countries. http://www.unesco.org/new/fileadmin/MULTIMEDIA/HQ/ED/pdf/CostingStudy.pdf
3. World Association for Sexual Health (WAS) (2008) Sexual health for the millennium. A declaration and technical document. Minneapolis, p 77. http://www.worldsexology.org/sites/default/files/Millennium%20Declaration%20(English).pdf
4. Personal Responsibility & Work Opportunity Reconciliation Act of 1996. Title V, § 510(b)(2)(A-H) of the Social Security Act. ftp://ftp.hrsa.gov/mchb/abstinence/statefs.pdf
5. Alford S (2001) What’s wrong with federal abstinence-only-until-marriage requirements? Transitions 12 3:4