1. T.C. Chang, Geometric reasoning : A key towards integrated process planning. School of industrial engineering, Purdue University, Indiana USA, CAM-I Features symposium, Boston, August 1990.
2. Pratt M. Automated feture recognition and its role in Product Modelling, Cranfield Institute of Technology, CAM-I Features symposium, Boston, August 1990.
3. van Houten F.J.A.M., PART : A computer aided Process Planning System, Proefschrift Enschede, 1991.
4. van Houtem F.J.A.M., van 't Erve A.H., Kals H.J.J., Part a Feature Based CAPP System, PA89-008, Februari 1989
5. ISO 10303-41 : Integrated resources : Fundamentals of Product description and support. ISO 10303-42 : Integrated resources : Geometric and Topological Representation.