1. Bloor, M. I. G., Wilson, M. J. and Hagen, H.: The smoothing properties of variational schemes for surface design. Computer Aided Geometric Design 12 (1995), 381–394.
2. de Boor, C.: A Practical Guide to Splines. Springer 1978.
3. Eck, M., Hoppe, H.: Automatic reconstruction of B-spline surfaces of arbitrary topological type. Preprint 1800, Technische Hochschule Darmstadt, 1996.
4. Farin, G.: Curves and Surfaces for Computer Aided Geometric Design — A Practical Guide. 3rd edition. Academic Press 1993.
5. Greiner, G.: Variational design and fairing of spline surfaces. Computer Graphics Forum 13: 3 (1994), 143–154.