Dzedzej, Zdzisław, and Wojciech Kryszewski. “Selections and Approximations of Convex-Valued Equivariant Mappings”. Topological Methods in Nonlinear Analysis 40, no. 2 (April 23, 2012): 381–414. Accessed April 26, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.2012.038.