Tijana Z. Dimitrijevic, Jugoslav J. Jokovic, and Nebojsa S. Doncov. “Frequency Adjustable Dual-Band Microstrip Gap-Ring-Slot Antenna Design Using the Cylindrical TLM Method”. The Applied Computational Electromagnetics Society Journal (ACES), vol. 34, no. 05, May 2019, pp. 631-4, https://journals.riverpublishers.com/index.php/ACES/article/view/8451.