O. Fedunyk-Yaremchuk, S. Hembars'ka, I. Romanyuk, and P. Zaderei, “Approximation characteristics of the Nikol’skii-Besov-type classes of periodic functions of several variables in the space $B_{q,1}$”, Carpathian Math. Publ., vol. 16, no. 1, pp. 158–173, Jun. 2024.