1. Boone, L.E. and Kurtz, D.L. (1999), Contemporary Marketing, The Dryden Press, Orlando, FL.
2. Curtis, M. (1998), available at: www.gopinnacle.com.
3. Devore, J.L. (1995), Probability and Statistics for Engineering and the Sciences, 4th ed., Duxbury Press, Belmont, CA.
4. Gabor, A. (1977), Pricing: Principles and Practices, Heinemann Educational Books, London.
5. Green, P.E. and Srinivasan, V. (1990), “Conjoint analysis in marketing: new developments with implications for research and practice”, Journal of Marketing, Vol. 54 No. 4, pp. 3‐19.