Jiraskulporn, P., P. Akkaakthalin, and S. Chaimoon. “Enhancement Microstrip Antenna Gain with Square Aperture Superstrate”. Journal of Advanced Development in Engineering and Science, vol. 2, no. 3, Aug. 2023, pp. 13-19, https://ph03.tci-thaijo.org/index.php/pitjournal/article/view/763.