1. Swedlow M (1974): Relief of Intactable Pain. Amsterdam: Excerpta Medica.
2. Wang JK, Nauss LE, Thomas JE (1979): Pain relief by intrathecally applied morphine in man. Anesthesiology 50: 149–151.
3. Daut RL, Cleeland CS (1982): The prevalence and severity of pain in cancer. Cancer 50: 1913–1918.
4. Evans RJ, Mackay IM (1972): Subarachnoid phenol blocks for relief of pain in advanced malignancy. Can J Surg 15: 50–53.
5. Ferrer-Brechner T (1984): Treating cancer pain as a disease. In: Benedetti C, Chapman C, Morricca G (eds), Advances in Pain Research and Therapy. New York: Raven Press, pp 575–591.