Aqeel Ahmed, Muhammad Yaseen, Asif Ali, and Rizwan Ali Shah. “Analysis of Microstrip Ring Resonator for 5G Communication at Different Operating Frequencies”. University of Sindh Journal of Information and Communication Technology , Vol. 4, no. 4, Dec. 2020, pp. 221 -26, https://sujo.usindh.edu.pk/index.php/USJICT/article/view/3296.