1. P. Brna, A. Bundy, T. Dodd, M. Eisenstadt, CK. Looi, H. Pain, B. Smith, M. van Someren, Prolog Programming Techniques, DAI Research Paper, 403, Department of Artificial Intelligence, University of Edinburgh, 1988
2. R. Burs tall, J. Darlington, Transformations for Developing Recursive Programs, J ACM, Vol. 24, No. 1,1977
3. Y. Deville, J. Burnay, Generalization and Program Schemata. Proceedings of the North American Conference on Logic Programming 1989, E. L. Lusk, R. A. Overbeek (eds.), MIT Press, October 1989, pp. 409-425.
4. J. Gallagher, Program Analysis and Transformation, Handout at Logic Programming Summer School LPSS’ 90, University of Zurich, August 1990
5. P. A. Gardner, J. C. Shepherdson, Unfold/Fold Transformations of Logic Programs, Report PM-89-01, School of Mathematics, University of Bristol, 1989