BodrayaV. I., NovikovO. A., & RukasovV. I. (2005). Approximation of Classes of ψ-Integrals of Periodic Functions of Many Variables by Rectangular Linear Means of Their Fourier Series. Ukrains’kyi Matematychnyi Zhurnal, 57(4), 564–570. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3622