GUIDE - P. SRIPRIYA, T. E. S. Secure Data hiding in Multi-level using Digital Invisible Ink based on Spread Spectrum Watermarking. International Journal of Engineering and Computer Science, india, v. 3, n. 08, 2014. Disponível em: https://ijecs.in/index.php/ijecs/article/view/1266. Acesso em: 22 jul. 2024.