1. The use of over-the-counter preparations by drug users attending an addiction treatment unit
2. Chemist and Druggist (2002) Chemist and Druggist Guide to OTC Medicines for Pharmacists and Pharmacy Assistants, 20th edn. CMP Information: Tonbridge.
3. Department of Health (1996) Task Force to Review Services to Drug Misusers, report to an independent review of drug treatment services in England. HMSO: London.
4. Department of Health (1999) Drug Misuse and Dependence-Guidelines on Clinical Management. HMSO: London.