H. Majeed, Abdul Rahman, and Enaam F. Adhab. “On Maps Of Period 2 On Prime Near – Rings”. Journal of Al-Qadisiyah for Computer Science and Mathematics, vol. 7, no. 2, Aug. 2017, pp. 72-79, https://jqcsm.qu.edu.iq/index.php/journalcm/article/view/66.