Wantana, Nuanthip, Smit Insiripong, Yotsaki Ruangthaweep, and Jakrapong Kaewkhao. “Study on Physical, Optical and Luminescence of Er<sup>3+</sup> in K<sub>2</sub>O-CaO-B<sub>2</sub>O<sub>3</sub> Glasses for Photonic Application”. Journal of Metals, Materials and Minerals 27, no. 1 (June 30, 2017). Accessed March 2, 2024. https://jmmm.material.chula.ac.th/index.php/jmmm/article/view/328.