1. EMCDDA. (2012). Statistical Bulletin 2012. Table GPS-8. Last 12 months prevalence of drug use in all available national general population surveys. Part (i) All adults (aged 15–64). Retrieved from http://www.emcdda.europa.eu/stats12#display:/stats12/gpstab8a.
2. The health of prisoners;Fazel;The Lancet,2011
3. Gallup. (2012). Illegal drugs. Retrieved from http://www.gallup.com/poll/1657/illegal-drugs.aspx
4. Harris Interactive. (2012, October 16–17). Le regard des Français sur la dépénalisation et la légalisation du cannabis.
5. Homeless people: Ex-prisoners in England and Wales;Jones,2012