1. Centers for Disease Control and PreventionCondoms and STDs: fact sheet for public health personnel2017-04-25https://www.cdc.gov/condomeffectiveness/docs/Condoms_and_STDS.pdf
2. UNAIDSUNFPAWorld Health OrganizationCondoms and HIV prevention: position statement by UNAIDS, UNFPA and WHO20092017-04-27http://who.int/hiv/pub/condoms/20090318_position_condoms.pdf?ua=1
3. World Health OrganizationGlobal strategy for the prevention and control of sexually transmitted infections: 2006–201520062017-04-25http://apps.who.int/iris/bitstream/10665/69361/1/WHO_RHR_06.10_eng.pdf
4. LaderDA report on research using the National Statistics Opinions Survey produced on behalf of the NHS Information Centre for health and social care2009https://pdfs.semanticscholar.org/a3a0/5c056cbcd7155996541a32d7d90d2fb4d487.pdf
5. Sexual behaviour in Britain: early heterosexual experience