StepanetsO. I. (1998) “Approximation of $\bar {\psi} - \text{Integrals}$ of periodic functions by Fourier sums (small smoothness). IIof periodic functions by Fourier sums (small smoothness). II”, Ukrains’kyi Matematychnyi Zhurnal, 50(3), pp. 388-400. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4938 (Accessed: 24November2024).