NON-INVASIVE GRADING TECHNIQUE FOR RUBY GEMSTONE USING CHARGE-COUPLED DEVICE (CCD) . ASEAN Engineering Journal, [S. l.], v. 13, n. 1, p. 69–74, 2023. DOI: 10.11113/aej.v13.18267. Disponível em: https://journals.utm.my/aej/article/view/18267.. Acesso em: 6 apr. 2025.