4Shan J J. Assessment of features technology[J]. CAD,1991, 23(5) :331--343.
5Shan J J. Expert form feature modeling shell[J]. CAD, 1998, 20(9):515--524.
6Winfried van Hollandl, Willem F Bronsvoor . Assembly features in modeling and planning[J]. Robotics and Computer Integrated Manufacturing, 2000,16 : 277-- 294.
7Christian Mascle. Feature--based assembly model for integration in computer--aided assembly[J]. Robotics and Computer Integrated Manufacturing, 2002 . 18:373--378.
8Christoph M Hoffmann. On user--defined features[J]. CAD,1998, 30(5):321--332.