Kalchuk IV, Kharkevych YI. I. Approximative properties of biharmonic Poisson integrals in the classes $W^r_{\beta} H^{\alpha}$. Ukr. Mat. Zhurn. [Internet]. 2016Nov.25 [cited 2024Nov.24];68(11):1493-504. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/1936