1. A. A. Samarskii, I. E. Kaporin, A. B. Kucherov, and E. S. Nikolaev, “Some modem methods of solution of grid equations,” Izv. Vyssh. Uchebn. Zaved., Matem., No. 7(254), 3–12 (1983).
2. S. I. Solov'ev, On the Spectrum of Finite-Element Approximation of the Eigenvalue Problem for the Laplace Operator [in Russian], Kazan' (1984), Unpublished manuscript, VINITI 30.7.84, No. 5517-84.
3. S. I. Solov'ev, “Fast solution methods for FEM grid schemes of second-order accuracy for the Poisson equation in a rectangle,” Izv. Vyssh. Uchebn. Zaved., Matem., No. 10(281), 71–74 (1985).
4. S. I. Solov'ev, “Fourier method for finite-element approximation of the Poisson equation,” in: Grid Methods for Solving Differential Equations [in Russian], Kazan' (1986), pp. 64–78.
5. P. Lancaster, Theory of Matrices [Russian translation], Moscow (1982).