Ernst W. Coetzee, Johann W. Odendaal, and Johan Joubert. “A Quad-Band Antenna With AMC Reflector for WLAN and WiMAX Applications”. Applied Computational Electromagnetics Society Journal (ACES), vol. 33, no. 10, July 2021, pp. 1123-8, https://journals.riverpublishers.com/index.php/ACES/article/view/8949.