Volchkov VV, Savost’yanova IM. Smoothing of the Singularities of Functions Whose Integrals over the Balls on a Sphere are Zero. Ukr. Mat. Zhurn. [Internet]. 2015 Feb. 25 [cited 2025 Apr. 7];67(2):272-8. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/1979