@Article {ddps.tissec,
    author = {E. Damiani and S. {De Capitani di Vimercati} and S. Paraboschi and P. Samarati},
    title = {A Fine-Grained Access Control System for {XML} Documents},
    journal = {ACM Transactions on Information and System Security (TISSEC)},
    volume = {5},
    number = {2},
    month = {May},
    year = {2002}
}