Othman, Adib, et al. “Convertible Bandstop to Allpass Filter Using Defected Ground Structure With Ideal Switch for Millimeter-Wave Band in 5G Application”. International Journal of Integrated Engineering, vol. 15, no. 3, Oct. 2023, pp. 193-8, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/14555.