P. Sam Johnson, Vinoth A, and K. Kamaraj. “Fuglede-Putnam Type Commutativity Theorems for EP Operators”. Malaya Journal of Matematik 9, no. 01 (January 1, 2021): 709–714. Accessed November 4, 2024. https://www.malayajournal.org/index.php/mjm/article/view/1117.