Monika Sester Lars Bernard Volker Paelke Advances in GIScience, Proceedings of the 12th AGILE Conference, Hannover, Germany, 2-5 June 2009 AGILE Conf. http://dx.doi.org/10.1007/978-3-642-00318-9 2009 978-3-642-00317-2 Lecture Notes in Geoinformation and Cartography Springer db/conf/agile/agile2009.html