Maristella Agosti Nicola Ferro Emanuele Panizzi Rosa Trinchese Annotation as a support to user interaction for content enhancement in digital libraries. 151-154 2006 conf/avi/2006 AVI http://doi.acm.org/10.1145/1133265.1133296 db/conf/avi/avi2006.html#AgostiFPT06