[1]
Y. S. Samoilenko and L. B. Turowska, “On bounded and unbounded idempotents whose sum is a multiple of the identity”, MFAT, vol. 8, no. 1, pp. 79–100, Mar. 2002, Accessed: Dec. 18, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/179