1. Partridge, Derek. Artificial Intelligence: applications in the future of software engineering. Halsted Press, Chichester: Ellis Horwood Limited, 1986.
2. Mc Kevitt, Paul. Data acquisition for natural language interfaces. Memoranda in Computer and Cognitive Science, MCCS-90–178, Computing Research Laboratory, Dept. 3CRL, Box 30001, New Mexico State University, Las Cruces, NM 88003–0001, 1990b.
3. Wilks, Yorick. One small head: models and theories. In “The foundations of Artificial Intelligence: a sourcebook”, Partridge, Derek and Yorick Wilks (Eds.), pp. 121–134. Cambridge, United Kingdom: Cambridge University Press, 1990.
4. Wilks, Yorick. Decidability and Natural Language. Mind, N.S. 80, 497–516, 1971.
5. Wilks, Yorick. Grammar, meaning and the machine analysis of language. London: Routledge and Keegan Paul, 1972a.