Fakhfakh, Majed, and Aref Jeribi. “Generalized Weakly Demicompact and $S$-Demicompact Linear Relations and Their Spectral Properties”. Ukrains’kyi Matematychnyi Zhurnal 75, no. 8 (August 30, 2023): 1119 - 1132. Accessed July 25, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/7194.