@book{TUW-121019, editor = {Mok, Esmond and Gartner, Georg}, title = {Proceedings of the 4. Internat. Symposium on Location Based Services {\&} TeleCartography}, publisher = {Department of Land Surveying {\&} Geo-Informatics, The HongKong Polytechnic University}, year = {2007}, address = {HongKong} }