Mel’nichenkoI. P., and PlaksaS. A. 1996. “Potential Fields With Axial Symmetry and Algebras of Monogenic Functions of a Vector Variable. II”. Ukrains’kyi Matematychnyi Zhurnal 48 (12), 1695-1703. https://umj.imath.kiev.ua/index.php/umj/article/view/5191.