A Steganographic Approach Based on Spetial Frequency Layering. Al-Nahrain Journal of Science, [S. l.], v. 9, n. 2, p. 69–72, 2018. Disponível em: https://mail.anjs.edu.iq/index.php/anjs/article/view/1659. Acesso em: 4 apr. 2025.