Samoilenko, A. M., O. I. Stepanets, and I. A. Shevchuk. 2004. “The international Conference „International Workshop on Analysis and Its applications"”. Ukrains’kyi Matematychnyi Zhurnal 56 (12), 1722. https://umj.imath.kiev.ua/index.php/umj/article/view/3880.