M. Felisa Verdejo Beatriz Barros J. Ignacio Mayorga Timothy Read Designing a Semantic Portal for Collaborative Learning Communities. 251-259 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3040&spage=251 2003 conf/caepia/2003 CAEPIA db/conf/caepia/caepia2003.html#VerdejoBMR03