J. Vermeulen, G. Vanderhulst, K. Luyten, and K. Coninx. Proceedings of the Sixth International Conference on Intelligent Environments (IE 2010), Kuala Lumpur, Malaysia, page 271--276. Los Alamitos, CA, IEEE Computer Society CPS, (2010)
M. Schneider, M. Velten, and J. Haupert. Proceedings of the Sixth International Conference on Intelligent Environments (IE 2010), Kuala Lumpur, Malaysia, page 122-127. Los Alamitos, CA, IEEE Computer Society CPS, (2010)