Hrabova, U. Z., I. V. Kalchuk, and T. A. Stepanyuk. “Approximation of Functions from the Classes $W_{β}^r H^{α }$ by Weierstrass Integrals”. Ukrains’kyi Matematychnyi Zhurnal 69, no. 4 (April 25, 2017): 510–519. Accessed April 11, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/1712.