1. Aït-Kaci, H. and Nasr, R. (1986). LOGIN: A Logic Programming Language with Built-in Inheritance.Journal of Logic Programming, 3(3), 185?215.
2. Allen, J.F. and Perrault, C.R. (1986). Analyzing Intention in Utterances. In B.J. Grosz, K.S. Jones, and B.L. Weber (Eds.),Readings in Natural Language Processing. Morgan Kaufmann, Los Altos, CA, pp. 441?458.
3. Baral, C., Kraus, S., and Minker, J. (1990). Communicating between multiple knowledge based systems with different languages.Draft Proc. Int. Working Conf. Cooperative Knowledge Based Systems, (pp. 121?125), University of Keele, England.
4. Brachman, R.J. (1983). What IS-A Is and Isn't: An Analysis of Taxonomic Links in Semantic Networks.Computer, 16(10), 30?36.
5. Chakravarthy, U. (1985).Semantic Query Optimization in Deductive Databases. Ph.D. thesis, University of Maryland, Department of Computer Science.