Siti Nurbaya Supardan, Rozan Mohammad Yunus, Suraya Ahmad Kamil, and Nurul Syaheera Razali, “Morphological, Structural and Optical Properties of Er3+-Doped SiO2-TiO2 Nanofiber”, IJNeaM, vol. 17, no. 1, pp. 92–97, Feb. 2024.