Dinca, George. “On the Kuratowski Measure of Noncompactness for Duality Mappings”. Topological Methods in Nonlinear Analysis 40, no. 1 (April 23, 2012): 181–187. Accessed July 22, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.2012.027.