1. Armstrong WW, Green M (1985) The Dynamics of Articulated Rigid Bodies for Purposes of Animation, Proc. Graphics Interface’85, Montreal, pp.407–416
2. Barr AH (1981) Superquadrics and Angle Preserving Transformations, IEEE Computer Graphics and Applications, Vol. 1, No 1, pp. 11–23
3. Barr AH (1984) Global and Local Deformations of Solid Primitives, Proc.SIGGRAPH’84, Computer Graphics, Vol. 18, No3, July 84
4. Bloomenthal J, Wyvill B. (1990) Interactive Techniques for Implicit Modeling, Proc. SIGGRAPH Symposium on Interactive 3D Graphics, Computer Graphics, Vol. 24, No 2, pp.109–116
5. Chadwick J, Haumann DR, Parent RE (1989) Layered Construction for Deformable Animated Characters, Proc. SIGGRAPH’89, Computer Graphics, Vol. 23, No3, pp.234–243