Romanyuk , A. S., and S. Ya. Yanchenko. “Kolmogorov Widths of the Nikol’skii – Besov Classes of Periodic Functions of Many Variables in the Space of Quasi-Continuous Functions”. Ukrains’kyi Matematychnyi Zhurnal, vol. 74, no. 2, Feb. 2022, pp. 220-32, https://doi.org/10.37863/umzh.v74i2.6932.