Herman Koto, M. I. H., and Elfarizanis Baharudin. “Single Layer Wide Angle Microwave Absorber for X Band Application With Bandwidth Enhancement”. Evolution in Electrical and Electronic Engineering, vol. 3, no. 2, Nov. 2022, pp. 958-67, https://publisher.uthm.edu.my/periodicals/index.php/eeee/article/view/8868.