Messirdi, Sofiane, Sanaa Messirdi, B. Sadli, and B. Messirdi. “A New Representation of Left and Right Generalized Drazin Invertible Operators”. Methods of Functional Analysis and Topology 27, no. 1 (March 25, 2021): 37–43. Accessed December 15, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/783.