@Article {cms.dke96,
author = {S. Castano and G. Martella and P. Samarati},
title = {Analysis, Comparison and Design of Role-Based Security Specifications},
journal = {Data & Knowledge Engineering (DKE)},
volume = {21},
number = {1},
pages = {31-55},
month = {December},
year = {1996}
}