Firliansyah, Aulia, Achmad Fauzi, and Hermansyah Sembiring. “Watermarking QR Code Application On Birth Certificates Using The Discrete Cosine Transform (DCT) Method”. Indonesian Journal of Education And Computer Science 1, no. 2 (August 31, 2023): 56–65. Accessed August 21, 2026. https://jurnal.intekom.id/index.php/indotech/article/view/46.