BurskiiV. P. “On the Third Boundary-Value Problem for an Improperly Elliptic Equation in a Disk”. Ukrains’kyi Matematychnyi Zhurnal 66, no. 2 (February 25, 2014): 279–283. Accessed November 23, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2130.