@article {IOPORT.50346214,
    author       = {Tirkel, Andrew Z. and Hall, Thomas E.},
    title        = {A unique watermark for every image},
    year         = {2001},
    journal      = {IEEE MultiMedia},
    volume       = {8},
    number       = {4},
    pages        = {30-37},
    identifier   = {50346214},
}