1. Agresti, A. (1990). Categorical Data Analysis, New York: John Wiley.
2. Airman, D.G. (1991). Practical Statistics for Medical Research. London: Chapman & Hall.
3. Barlow, D.H. and Hersen, M. (1984). Single-case Experimental Designs: Strategies for Studying Behaviour Change, 2nd edn. New York: Pergamon Press.
4. Bland, J.M. (1995). An Introduction to Medical Statistics. Oxford: Oxford University Press.
5. Chow, S.L. (1996). Statistical Significance: Rationale, Validity and Utility. London: Sage.