Gryshchuk, S. V., and S. A. Plaksa. 2009. “Integral Representations of Generalized Axially Symmetric Potentials in a Simply Connected Domain”. Ukrains’kyi Matematychnyi Zhurnal 61 (2), 160-77. https://umj.imath.kiev.ua/index.php/umj/article/view/3012.