@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}
}