Eicke Godehardt Nadeem Bhatti Using Topic Maps for Visually Exploring Various Data Sources in a Web-Based Environment. 51-56 2007 TMRA http://dx.doi.org/10.1007/978-3-540-70874-2_6 conf/tmra/2007 db/conf/tmra/tmra2007.html#GodehardtB07