1. American College of Physicians Health and Public Committee (1983) Drug therapy for severe chronic pain in terminal illness. Ann Intern Med 99:870
2. American Pain Society (1989) Principles of analgesic use in the treatment of acute pain and chronic cancer pain. A concise guide to medical practice, 2nd edn, Skokie, Illinois: American Pain Society
3. Arkinstall WW, Goughnor BR, White JA, Stewart JH (1989) Control of severe pain with sustained-release morphine tablets vs. oral morphine solution. Can Med Assoc J 140:653
4. Beaver W (1984) Combination analgesics. Am J Med 77:38
5. Beaver W, Wallenstein S, Houde R, Rogers A (1966) Comparison of the analgesic effects of pentazocine and morphine in patients with cancer. J Pharmacol Ther 7:740