Kristály, Alexandru, and Csaba Varga. “A Set-Valued Approach to Hemivariational Inequalities”. Topological Methods in Nonlinear Analysis 24, no. 2 (December 1, 2004): 297–307. Accessed April 26, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.2004.029.