U. AHMED, S. AFRIDI, SANAULLAH, M. R. ANJUM, and A. A. JAMALI. “Ultra-Improved Stop Band Rejection of an Ceramic Filter Using Ridge Resonators”. Sindh University Research Journal - SURJ (Science Series), Vol. 52, no. 1, Mar. 2020, https://sujo.usindh.edu.pk/index.php/SURJ/article/view/593.