D.  Hu and Li, Q., ?A practical and secure buyer-seller watermarking protocol?, Journal of Digital Information Management, vol. 9, no. 1, pp. 43 - 47, 2011.

X.  Xu, Tomlinson, M., Ambroze, M., and Ahmed, M., ?Biorthogonal matrix dirty paper coding for information hiding in still images?, Journal of Digital Information Management, vol. 7, no. 2, pp. 96 - 105, 2009.