1. United Nations Office on Drugs and Crime (UNODC) (2013) World Drug Report 2013. http://www.unodc.org/unodc/secured/wdr/wdr2013/World_Drug_Report_2013.pdf . Accessed 21 September 2013
2. Substance Abuse and Mental Health Services Administration (2012) Results from the 2011 National Survey on Drug Use and Health: Summary of National Findings. NSDUH Series H-44. U.S. Department of Health and Human Services, Rockville. http://www.samhsa.gov/data/NSDUH/2012SummNatFindDetTables/NationalFindings/NSDUHresults2012.htm . Accessed 21 September 2013.
3. Drummer OH, Kourtis I, Beyer J, Tayler P, Boorman M, Gerostamoulos D (2012) The prevalence of drugs in injured drivers. Forensic Sci Int 215:14–17
4. Lacey JH, Kelley-Baker T, Furr-Holden D, Voas RB, Romano E, Ramirez A, Brainard K, Moore C, Torres P, Berning A (2009) 2007 National Roadside Survey of Alcohol and Drug Use by Drivers: Drug Results. National Highway Traffic Safety Administration Office of Behavioral Safety Research. http://www.nhtsa.gov/Driving+Safety/Research+&+Evaluation/ci.2007+National+Roadside+Survey+of+Alcohol+and+Drug+Use+by+Drivers.print . Accessed 21 September 2013.
5. Mazur A, Lichti CF, Prather PL, Zielinska AK, Bratton SM, Gallus-Zawada A, Finel M, Miller GP, Radomińska-Pandya A, Moran JH (2009) Characterization of Human Hepatic and Extrahepatic UDP-Glucuronosyltransferase Enzymes Involved in the Metabolism of Classic Cannabinoids. Drug Metab Dispos 37(7):1496–1504