1. de Boor C. (1978) A Practical Guide to Splines. Springer Verlag, Berlin.
2. de Boor C. (1976). Splines as Linear Combinations ofB-Splines. A Survey, in Approximation Theory In Lorentz G.G., Chui C.K., and Schumaker L.L., eds, Academic Press, New York.
3. Chen G., Chu, C.K., Lai M.J. (1986), Construction of Real-Time Quasi-Interpolation Schemes, CAT Report #107, Texas A & M University.
4. Butzer, P.L., Schmidt, M., Stark, E.L., Vogt, L. (1989), Central Factorial Numbers, their Main Properties and Some Applications. Numer. Funct. Anal. and Optimiz. 10, 419–488.
5. Butzer, P.L., Schmidt, M. (1990), Central Factorial Numbers and their Role in Finite Difference Calculus and Approximation, in Approximation Theory, Szabados J. and Tandori K. eds, Colloquia Mathematica, Soc. Janos Bolyai 58, North Holland.