David W. Chadwick Gansen Zhao Sassa Otenko Romain Laborde Linying Su Tuan-Anh Nguyen PERMIS: a modular authorization infrastructure. 1341-1357 2008 20 Concurrency and Computation: Practice and Experience 11 http://dx.doi.org/10.1002/cpe.1313 db/journals/concurrency/concurrency20.html#ChadwickZOLSN08