1. Conte, S. D., de Boor, C.: Elementary Numerical Analysis, An Algorithmic, Approach. International Student Edition, McGraw-Hill, Kogakusha Ltd. 1980.
2. Joshi, T. C., Saxena, R. B.: On quartic spline interpolation. Ganita33, 97–111 (1982).
3. Varga, R. S.: Matrix Iterative Analysis. Englewood Cliffs, N. J.: Prentice-Hall 1962.