3. Anil, Bhatia(1999), Customer Relationship Management, lst ed U.S.A.;Don Hull. Dewar, Robert D. and Jane E. Dutton(1986). “The Adoption of Radical and Incremental Innovations: An Empirical Analysis.
4. Babin, B. J. and W. R.Darden & M. Griffin,(1994), "Work and/or Fun:Measuring Hedonic and Utilitarian Shopping Value, " Journal of Consumer Research, Vol. 20 (4), pp.644-656.