TwycrossRG.: Opioid analgesics in cancer pain: current practice and controversiesCancer Surv1988; 7: 29–53.
2.
PortenoyRK, FoleyKM, InturrisiCE.: The nature of opioid responsiveness and its implications for neuropathic pain: new hypothesis derived from studies of opioid infusionsPain1990; 43: 273–286.
3.
VentafriddaF, TamburiniM, CaraceniA, De ConnoF, NaldeiF.: A validation study of the WHO method for cancer pain reliefCancer1987; 59: 850–856.
4.
AshburnMA, LipmanAG.: Management of pain in the cancer patientAnesth Analg1993; 76: 402–416.
5.
MoriccaG.Chemical hypophysectomy for cancer pain. In: BonicaJJ (ed). Advances in Neurology.Volume IV. New York:Raven Press, 1974: 707–714.