title: supporting periodic authorizations and temporal reasoning in database access control 1996. authors: elena ferrari , pierangela samarati , claudio bettini , elisa bertino. venue: vldb. year: nan
title: an access control model supporting periodicity constraints and temporal reasoning elisa bertino , claudio bettini , elena ferrari , pierangela samarati. authors: nan. venue: acm transactions on database systems ( tods ). year: 1998.0