Tran, Lam, Hieu Le, Vinh Tran, and Van Tran. 2014. “Influence of SnO2 Concentration on the Structure and Optical Properties of Erbium Doped SiO2-SnO2 Ceramic Glass Thinfilms”. Science and Technology Development Journal 17 (3), 92-97. https://doi.org/https://doi.org/10.32508/stdj.v17i3.1374.