1. Aben, M. W. M. M. (1989) Knowledge base refinement: A logic-programming approach. Technical Report 1016 BS Amsterdam, Dept. of Social Science Informatics, University of Amsterdam.
2. Bareiss, E. R., Porter, B. W. and Wier, C. C. (1989) Protos: An exemplar-based learning apprentice. In Y. Kodratoff and R. S. Michalski, (eds.), Machine Learning: An Artificial Intelligence Approach, Volume 3, Morgan Kaufmann.
3. Barr, A. and Feigenbaum, E. (Eds.) (1981) The Handbook of Artificial Intelligence, Addison Wesley, pp. 216 ff.
4. Borgida, A., Mitchell, T. and Williamson, K. E. (1985) Learning improved integrity constraints and schemas from exceptions in data and knowledge bases, in M. L. Brodie and J. Mylopoulos (Eds.), On Knowledge Based Management Systems, NY, Springer Verlag.
5. Buchanan, B. G. and Mitchell, T. (1978) Model-directed learning of production rules. In Pattern-Directed Inference Systems, pp. 297?312, New York, Academic Press.