For citations:

Tukhliev K. MEAN-SQUARE APPROXIMATION OF FUNCTIONS BY FOURIER–BESSEL SERIES AND THE VALUES OF WIDTHS FOR SOME FUNCTIONAL CLASSES. Chebyshevskii Sbornik. 2016;17(4):141-156. (In Russ.) https://doi.org/10.22405/2226-8383-2016-17-4-141-156