kadham Al-talkany, Yiezi, Ameer A.J. AL-Swidi, and Ali Younis Shaker. “Topological Study via σ-Algebra”. Journal of Al-Qadisiyah for Computer Science and Mathematics 8, no. 1 (August 9, 2017): 78–82. Accessed November 15, 2024. https://jqcsm.qu.edu.iq/index.php/journalcm/article/view/46.