Minenko, A. S. “Analyticity of a Free Boundary in One Problem of Axisymmetric Flow”.
Ukrains’kyi Matematychnyi Zhurnal
50, no. 12 (December 25, 1998): 1692–1700. Accessed April 27, 2025.
https://umj.imath.kiev.ua/index.php/umj/article/view/4789
.