1. S. Katzenbeisser, F. Petitcolas, Information hiding techniques for steganography and digital watermarking, Computer Security Series, Artech House, 2000.
2. C. Kurak, J. McHugh, A cautionary note on image downgrading, In: Proceedings of IEEE Eight Annual Comput Security Applications Conference, San Antonio, USA, Nov./Dec. 1992, pp. 153–155.
3. I. Moskowitz, G. Longdon, L. Chang, A new paradigm hidden in steganography, In: Proceedings of Workshop on new security paradigms, Ballycotton, Country Cork, Ireland, ACM Press, New York, 2000, pp. 41–50.
4. T. Sharp, An implementation of key-based digital signal steganography, In: Proceedings of Fourth International Workshop on Information Hiding, Pittsburgh, USA, Springer, LNCS, vol. 2137, 2001, pp. 13–26.
5. E. Kawaguchi, R. Eason, Principle and applications of BPCS-Steganography, In: Proceedings of Multimedia Systems and Applications Conference, Boston, MA, USA, SPIE series, vol. 3528, 1998, pp. 464–473.