Schwartz D, Lellouch J. Explanatory and pragmatic attitudes in therapeutic trials. J Chron Dis1967; 20: 637–648.
2.
Twycross RG. Choice of strong analgesic in terminal cancer: diamorphine or morphine?Pain1977; 3: 93–104.
3.
Twycross RG. The effects of cocaine in the Brompton Cocktail. In: Bonica JJ, Liebeskind JC, Albe-Fessard DG eds. Advances in pain research and therapy, Vol 3. New York: Raven Press, 1979: 927–932.
