Bazalii, B.V. (1998) “On one proof of the classical solvability of the Hele-Shaw problem with free boundary”,
Ukrains’kyi Matematychnyi Zhurnal, 50(11), pp. 1452–1462. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/4797 (Accessed: 14 April 2025).