@Article {BCDDFPS.cose2010,
author = {C. Blundo and S. Cimato and S. {De Capitani di Vimercati} and A. {De Santis} and S. Foresti and S. Paraboschi and P. Samarati},
title = {Managing Key Hierarchies for Access Control Enforcement: Heuristic Approaches},
journal = {Computers & Security},
volume = {29},
number = {5},
pages = {533-547},
month = {July},
year = {2010}
}