1. Landay, J.A., Myers, B.A.: Sketching interfaces: Toward more human interface design. IEEE Computer 34(2), 56–64 (2001)
2. Eggli L., Brüderlin B. P., Elber G.: Sketching as a solid modeler tool, Third Symposium on Solid Modeling and Applications, ACM SIGGRAPH, pp. 313–321 (1995)
3. Pugh, D.: Designing solid objects using interactive sketch interpretation. Computer Graphics Symposium on Interactive 3D Graphics 25(2), 117–126 (1992)
4. Hu, H.-q.: Freehand Sketch-based Three-dimensional CAD System, Zhejiang University (2004)
5. C.-x. Ma.: Research on Gesture Description and Sketch Design System in Conceptual Design PhD thesis, Chinese Academy of Sciences (2003)