Duarte Júnior, J. G., and V. P. da Silva Neto. “A Novel Tri-Bandpass Filter Side-Coupled Square Ring Based ”. Journal of Microwaves, Optoelectronics and Electromagnetic Applications (JMOe) 19, no. 2 (May 11, 2020): AoP 265-275. Accessed June 4, 2020. http://www.jmoe.org/index.php/jmoe/article/view/850.