BarnyakM. Y. “Construction of the Solutions of Boundary-Value Problems for the Laplace Equation in Domains of Revolution With Edged Boundary”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 61, no. 5, May 2009, pp. 579-95, https://umj.imath.kiev.ua/index.php/umj/article/view/3043.