1. Birkhoff, G., Fix, G.: Accurate eigenvalue computations for elliptic problems. In Numerical Solution of Field Problems in Continuum Physics, G. Birkhoff and R. Varga, eds., American Mathematical Society, Providence, 1970, pp. 111?151
2. Canosa, J., Gomes de Olivera, R.: A new method for the solution of the Schrodinger equation. J. Computational Phys.5, 188?207 (1970)
3. Collatz, L.: The Numerical Treatment of Differential Equations. Berlin: Springer 1966
4. Davis, P., Rabinowitz, P.: Numerical Integration. Boston: Ginn-Blaisdell, 1967
5. de Boor, C., Swartz, B.: Collocation at Gaussian points, SIAM J. Numer. Anal.10, 582?606 (1973)