Lima, A. M., N. H. O. Cunha, and J. P. da Silva. “Effect of Metamaterial Cells Array on a Microstrip Patch Antenna Design”. Journal of Microwaves, Optoelectronics and Electromagnetic Applications (JMOe) 19, no. 3 (July 9, 2020): AoP 327-342. Accessed August 14, 2020. http://www.jmoe.org/index.php/jmoe/article/view/886.