@InProceedings {jss.oak97,
    author = {S. Jajodia and P. Samarati and {V.S.} Subramanian},
    booktitle = {Proc. of the 1997 IEEE Symposium on Security and Privacy},
    title = {A Logical Language for Expressing Authorizations},
    address = {Oakland, CA},
    month = {May},
    year = {1997}
}