@Article {bjs.tois99,
    author = {E. Bertino and S. Jajodia and P. Samarati},
    title = {A Flexible Authorization Mechanism for Relational Data Management Systems},
    journal = {ACM Transactions on Information Systems (TOIS)},
    volume = {17},
    number = {2},
    month = {April},
    year = {1999}
}