Sirovnik, Nejc. “On Certain Functional Equation in Semiprime Rings and Standard Operator Algebras”. CUBO, A Mathematical Journal 16, no. 1 (March 1, 2014): 73–80. Accessed May 18, 2024. https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1289.