Gölbaşı, Ö., et al. “On Centralizing and Strong Commutativity Preserving Maps of Semiprime Rings”. Ukrains’kyi Matematychnyi Zhurnal, vol. 67, no. 2, Feb. 2015, pp. 279-85, https://umj.imath.kiev.ua/index.php/umj/article/view/1980.