Boyka Gradinarova Ognjan Zhelezov Milena Gradinarova An e-Learning Application Based on the Semantic Web Technology. 75-82 2006 conf/ifip3/2006 Education for the 21st Century http://dx.doi.org/10.1007/978-0-387-34731-8_9 db/conf/ifip3/ifip3-2006.html#GradinarovaZG06