@InProceedings {DS.nswp96,
    author = {S. {De Capitani di Vimercati} and P. Samarati},
    booktitle = {Proc. of the ACM SIGSAC New Security Paradigms Workshop},
    title = {Access Control in Federated Systems},
    address = {Lake Arrowhead, CA, USA},
    month = {September},
    year = {1996}
}