1. R. Ayala, E. Domínguez, A.R. Francés, A. Quintero, and J. Rubio, “On surfaces in digital topology,” in Proceedings of the 5th Colloquium of Discrete Geometry for Computer Imagery DGCI,’95. (1995) pp. 271,–276.
2. Ch.K. Chui Multivariate Splines. Texas A&M University CBMS-NSF Regional conferences Series in Applied Mathematics Philadelphia Pennsilvania. 1988.
3. J.H. Conway and N.J.A. Sloane Sphere Packing Lattice and Groups Second edition, Springer-Verlag, A series of comprehensive studies in mathematics. 1993.
4. H.S.M. Coxeter, Introduction to Geometry, 2nd edition, John Wiley & Sons Inc. 1969.
5. E.R. Dougherty, “Mathematical Morphology in Image Processing,” Marcel Dekker, New York 1991.