Vakarchuk, S.B. and Vakarchuk, M.B. 2022. $K$-functionals and extreme problems of the theory of approximation of the classes of analytic functions in a circle. II. Ukrains’kyi Matematychnyi Zhurnal. 74, 7 (Aug. 2022), 921 - 929. DOI:https://doi.org/10.37863/umzh.v74i7.6981.