1. Huang, S., Wu, J.K.: Optical watermarking for printed document authentication. IEEE Trans. Inf. Forensics Secur. 2(2), 164–173 (2007)
2. Rashid, A.: Digital watermarking applications and techniques: a brief review. Int. J. Comput. Appl. Technol. Res. 5(3), 147–150 (2016)
3. Sun, Q.B., Feng, P.R., Deng, R.: An optical watermarking solution for authenticating printed documents. In: Proceedings International Conference on Information Technology: Coding and Computing, pp. 65–70. IEEE (2001)
4. Lecture Notes in Computer Science;M Naor,1995