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2. Convex approximation by splines;Beatson, R. K.;SIAM J. Math. Anal.,1981
3. Smooth surface interpolation;Birkhoff, Garrett;J. Math. and Phys.,1960
4. On calculating with 𝐵-splines;de Boor, Carl;J. Approximation Theory,1972
5. C. de Boor, "Splines as linear combination of B-splines," in Approximation Theory II (G. G. Lorentz, C. K. Chui, L. L. Schumaker, Eds.), Academic Press, New York, 1976, pp. 1-47.