1. Legal opioid consumption in Denmark 1981-1993;Clausen;Eur J Clin Pharmacol,1995
2. 2. World Health Organisation (WHO).Cancer pain relief. Geneva: WHO, 1986.
3. 3. World Health Organisation (WHO).Cancer pain relief and palliative care: report of a WHO expert committee. Geneva: WHO, 1990.
4. 4. Personal communication.