PlaksaS. A. “On Integral Representations of an Axisymmetric Potential and the Stokes Flow Function in Domains of the Meridian Plane. I”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 53, no. 5, May 2001, pp. 631-46, https://umj.imath.kiev.ua/index.php/umj/article/view/4286.