1. (London: British Medical Association)pp1-2Swinscow T D V1983Statistics at Square One 8th edn(London:British
2. Chapter 7 Lipschutz S 1974 Theory and Problems of Probability Schaum's Outline Series
3. (New York: McGraw-Hill)p119Kreyszig E1977Statistische Methoden und ihreAnwendungen (Gottingen:
4. versus radiation plus placebo in the treatment of head and neck cancer Int. J.