Gavrilyuk, V.T. (1990) “Asymptotic estimates of approximation of continuous periodic functions by the Fourier sums ”, Ukrains’kyi Matematychnyi Zhurnal, 42(6), pp. 747–755. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8830 (Accessed: 10 April 2025).