Lasuriya RA. Direct and inverse theorems on approximation of functions defined on a sphere in the space S (p,q)(σ m). Ukr. Mat. Zhurn. [Internet]. 2007Jul.25 [cited 2024Nov.22];59(7):901-1. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/3355