1. Abo, A.V. and Ullman, J.D. (1972) The theory of Parsing, Translation and Compiling, Vol: Parsing, Prentice-Hall, Englewood Cliffs, N.J.
2. Berg-Cross, G. and Price, M. E. (1989) Acquiring and managing knowledge using a conceptual structures approach, IEEE Transactions on Systems, Man and Cybernetics, vol. 19:3, p.513–27.
3. Calder, J., Klein, E., and Zeevat, H. (1988) Unification Categorial Grammar: A Concise Extendable Grammar for Natural Language Processing, COUNG-88, 83–86.
4. Clocksin, W. and Mellish, C. (1981) Programming in PROLOG, Springer-Verlag: Berlin.
5. Dowty, D. R., Wall, R. E., and Peters, S., Introduction to Montague Semantics, Reidel, Dortrecht, 1981