1. Cancer pain relief;WHO Expert Committee,1986
2. Pain in infants, children, and adolescents;Schechter,1993
3. Looking forward to cancer pain relief for all—international consensus on the management of cancer pain;WHO Expert Committee,1997
4. Pain and its effects on the human neonate and fetus;Anand;N Engl J Med,1987
5. Addiction rare in patients treated with narcotics;Porter;N Engl J Med,1980