Thang , Kieu Vu, Nguyen Thanh Tung, and Ewald Janssens. “Microwave Metamaterial-Based Superlens for Energy Focusing Applications”. <i>Vietnam Journal of Science and Technology</i> 56, no. 6 (December 17, 2018): 698–705. Accessed January 10, 2026. https://vjs.ac.vn/jst/article/view/12722.