J. Farhan, Malik, Zaid A. Abed Al-Hussein, and Sarab K. 2009. “Bandwidth Improvement of Microstrip Antenna Using Multi-Resonator Elements With Stacked Geometry”. Journal of Engineering and Sustainable Development 13 (4): 86-105. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1519.