@Article {dqs.dapd00,
    author = {S. Dawson and S. Qian and P. Samarati},
    title = {Providing Security and Interoperation of Heterogeneous Systems},
    journal = {Distributed and Parallel Databases},
    volume = {8},
    number = {1},
    pages = {119-145},
    month = {January},
    year = {2000}
}