@InCollection {bs.lead03,
author = {P. Bonatti and P. Samarati},
editor = {J. Chomicki and R. {van der Meyden} and G. Saake},
booktitle = {Logics for Emerging Applications of Databases},
title = {Logics for Authorizations and Security},
publisher = {Springer-Verlag},
year = {2003}
}