WASET
    Mussarat Abdullah and  Fazal Wahab,  Key Based Text Watermarking of E-Text Documents in an Object Based Environment Using Z-Axis for Watermark Embedding.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2008, vol. 22(10). 3341 - 3344
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/6265.