1. Drug penalties The Home Office, UK http://www.homeoffice.gov.uk/drugs/drug-law/
2. National Organization for the Reform of Marijuana Laws 2003 European Drug Policy: 2002 Legislative Update http://norml.org/component/zoo/category/european-drug-laws
3. European Monitoring Centre for Drug and Drug Addiction 2010 Illegal Consumption of Drugs http://www.emcdda.europa.eu/html.cfm/index5747EN.html
4. National Treatment Agency for Substance Misuse 2009 Breaking the link: The role of drug treatment in tackling the crime http://www.nta.nhs.uk/uploads/nta_criminaljustice_0809.pdf