FIRLIANSYAH, A.; FAUZI, A.; SEMBIRING, H. Watermarking Qr Code Application On Birth Certificates Using The Discrete Cosine Transform (Dct) Method. Indonesian Journal of Education And Computer Science, [S. l.], v. 1, n. 2, p. 56–65, 2023. DOI: 10.60076/indotech.v1i2.46. Disponível em: https://jurnal.intekom.id/index.php/indotech/article/view/46. Acesso em: 11 oct. 2025.