AbdmoulehF., and Ben LakhalT. “Left and Right B-Fredholm Operators”. Ukrains’kyi Matematychnyi Zhurnal 74, no. 10 (November 27, 2022): 1299 - 1307. Accessed November 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6331.