Fedunyk-Yaremchuk, O. and Hembars’ka, S. (2022) “Best orthogonal trigonometric approximations of the Nikol’skii-Besov-type classes of periodic functions of one and several variables”, Carpathian Mathematical Publications, 14(1), pp. 171–184. doi: 10.15330/cmp.14.1.171-184.