@article{Kotova_Trigub_2012, title={Exact order of approximation of periodic functions by one nonclassical method of summation of Fourier series}, volume={64}, url={https://umj.imath.kiev.ua/index.php/umj/article/view/2631}, abstractNote={By using an exact estimate for approximation by known trigonometric polynomials, we strengthen a Jackson-type theorem. Moreover, we determine the exact order of approximation of some periodic functions by these polynomials. For this purpose, we introduce a special modulus of smoothness.}, number={7}, journal={Ukrains’kyi Matematychnyi Zhurnal}, author={Kotova, O. V. and Trigub, R. M.}, year={2012}, month={Jul.}, pages={954-969} }