@InProceedings{ pretschner.ea:usage:2007, author = {A. Pretschner and M. Hilty and F. Massacci}, booktitle = {3rd Intl. Conf. on Trust, Privacy & Security in Digital Business}, language = {USenglish}, month = 9, pages = {83--93}, publisher = {Springer}, series = {LNCS}, title = {Usage Control in Service-Oriented Architecture}, volume = 4657, year = 2007, user = {pretscha} }