Zabavsky, B. V., O. V. Domsha, and O. M. Romaniv. “Clear Rings and Clear Elements”. Matematychni Studii 55, no. 1 (March 3, 2021): 3-9. Accessed December 28, 2024. http://matstud.org.ua/ojs/index.php/matstud/article/view/126.