1. BeanP. (1974). The Social Control of Drugs. Martin Robertson, Bath.
2. BucknallA.B.V. and RobertsonJ.R. (1986). Deaths of Heroin Users in a General Practice Population, Journal of the Royal College of General Practitioners, 36, March, pp. 120–122.
3. CoomberR. (1997c). Dangerous Drug Adulteration—An International Survey of Drug Dealers Using the Internet and the World Wide Web (WWW), The International Journal of Drug Policy, in press.
4. Drug Enforcement Administration (1991). Domestic Monitor Program, 1991 Annual Summary. U.S. Government Printing Office, Washington, D.C.