1. Poigembositm, E. A, McCorduck, P and N.H, HP(1998) The Rise of the Export Company, Times Books, New York.
2. Gagne ËD. Yokovich, C,W and Yokovich, FR(1993) The Cognnitive Psychology of School Learning, HarperCollins College publishers, New York.
3. Kim, W (1995) Modern databases? systems: the object model interaperability, and beyond, ACM Press and Addision NewYork.
4. Mitchell, T.M (1997) Decision free learning in Machine Learning, McGaw-Hill Coropefty,NewYork.
5. Scimotter, J W (1998) Portfolio system at Haworth College of Business, available online: hflp://www.hcob.wmich, edu/portfblio/