1. D. Alberg, E. Nielson, and L. Walsh, Theory of Splines and Its Application [Russian translation], Mir, Moscow (1972).
2. S. A. Ambartsumyan, Theory of Anisotropic Shells [in Russian], Fizmatgiz, Moscow (1961).
3. R. Bellman and R. Kalaba, Quasi-linearization and Nonlinear Boundary-Value Problems [Russian translation], Mir, Moscow (1968).
4. K. Z. Galimov, Principles of the Nonlinear Theory of Thin Shells [in Russian], Izd-vo Kazan. Un-ta, Kazan (1987).
5. S. K. Godunov, “Numerical solution of boundary-value problems for systems of linear ordinary differential equations,” Usp. Mat. Nauk,16, No. 3, 171–174 (1961).