1. CONSURF part one: introduction to conic lifting tile;Ball;Comput. Aided Design,1974
2. Barsky, B. A., The beta-spline: a local representation based on shape parameters and fundamental geometric measures, Ph.D. dissertation, University of Utah, 1981.
3. Beśka, M., Convexity and variation diminishing property of multidimensional Bernstein polynomials, Ph.D. dissertation, University of Gdańsk, 1988.
4. Curvature continuous curves and surfaces;Boehm;Comput. Aided Geom. Design,1985
5. Smooth curves and surfaces;Boehm,1987