Messirdi, So., Sa. Messirdi, and B. Messirdi. “Further Results on Left and Right Generalized Drazin Invertible Operators”. Matematychni Studii 54, no. 1 (October 6, 2020): 98-106. Accessed December 9, 2021. http://matstud.org.ua/ojs/index.php/matstud/article/view/57.