On the 90th anniversary of Professor Toleubay Idrisovich Amanov (25.08.1923–21.06.1978) O. V. Besov, V. I. Burenkov, T. Sh. Kalmenov, R. Oinarov, M. Otelbaev, E. S. Smailov

5

The O'Neil inequality for the Hankel convolution operator and some applications C. Aykol, V. S. Guliyev, A. Serbetci.

8

An inverse problem for the matrix quadratic pencil on a finite interval N. P. Bondarenko

20

Addition of lower order terms preserving almost hypoellipticity of polynomials H. G. Ghazaryan

32

On spectral properties of a periodic problem with an integral perturbation of the boundary condition N. S. Imanbaev, M. A. Sadybekov

53

New examples of Pompeiu functions G. A. Kalyabin

63

A maximum principle in spectral optimization problems for elliptic operators subject to mass density perturbations P. D. Lamberti, L. Provenzano

70

Qualitative properties of structurally damped wave models S. Matthes, M. Reissig

84

Properties of singular integrals in terms of maximal functions measuring smoothness R. M. Rzaev

107

Best polynomial approximations and widths of certain classes of functions in the space G. A. Yusupov

120

An inequality for the weighted Hardy operator for N. Azzouz, B. Halim, A. Senouci

127

Mathematical model of the gas flow in the shock front S. K. Matveev, N. Zh. Jaichibekov

132

Applications of Sobolev lattice cubature formulas M. D. Ramazanov, D. Y. Rakhmatullin

137
