C. Grompanopoulos and I. Mavridis, Towards Differentiated Utilization of Attribute Mutability for Access Control in Ubiquitous Computing, 2010 14th Panhellenic Conference on Informatics, pp.118-123, 2010.
DOI : 10.1109/PCI.2010.45

B. Katt, X. Zhang, R. Breu, M. Hafner, and J. P. Seifert, A general obligation model and continuity, Proceedings of the 13th ACM symposium on Access control models and technologies , SACMAT '08, pp.123-132, 2008.
DOI : 10.1145/1377836.1377856

J. Park and R. Sandhu, usage control model, ACM Transactions on Information and System Security, vol.7, issue.1, pp.128-174, 2004.
DOI : 10.1145/984334.984339

R. K. Thomas and R. Sandhu, Models, protocols, and architectures for secure pervasive computing: challenges and research directions, IEEE Annual Conference on Pervasive Computing and Communications Workshops, 2004. Proceedings of the Second, pp.164-168, 2004.
DOI : 10.1109/PERCOMW.2004.1276925

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.161.878

X. Zhang, F. Parisi-presicce, R. Sandhu, and J. Park, Formal model and policy specification of usage control, ACM Transactions on Information and System Security, vol.8, issue.4, pp.351-387, 2005.
DOI : 10.1145/1108906.1108908

URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.161.2670

X. Zhang, R. Sandhu, and F. Parisi-presicce, Safety analysis of usage control authorization models, Proceedings of the 2006 ACM Symposium on Information, computer and communications security , ASIACCS '06, pp.243-254, 2006.
DOI : 10.1145/1128817.1128853