Gustafsson, Björn, and Yu-Lin Lin. “On the Dynamics of Roots and Poles for Solutions of the Polubarinova-Galin Equation”. Annales Fennici Mathematici 38, no. 1 (February 1, 2013): 259–286. Accessed November 22, 2024. https://afm.journal.fi/article/view/135434.