1. M. Abramowitz and I. Stegun (eds.), Handbook
of Mathematical Functions with Formulas, Graphs and Mathematical Tables (U.S.
Department of Commerce, Washington, 1964).
2. S. D. Algazin, “Localization of eigenvalues of closed linear operators,” Sib.
Matem. Zh. 24, (1983) [Siberian Math. J. 24, 155 (1983)].
3. S. D. Algazin and I. A. Kiĭko, Flutter
of Plates and Shells (Nauka, Moscow, 2006) [in Russian].
4. N. N. Anuchina, K. I. Babenko, S. K. Godunov, N. A. Dmitriev, L. A.
Dmitrieva, V. F. D’yachenko, A. V. Zabrodin, O. V. Lokutsievskiĭ, E. V.
Malinovskiĭ, I. F. Podlivaev, G. P. Prokopov, I. D. Sofronov, and R. P. Fedorenko,
Theoretical Principles and Construction of Numerical Algorithms of
Mathematical Physics (Nauka, Moscow, 1979) [in Russian].
5. K. I. Babenko, “Approximation of periodic functions of many variables by
trigonometric polynomials,” Dokl. Akad. Nauk SSSR 132,
247 (1960) [Soviet Math., Dokl. 1, 513
(1960)].