4172 2006 Research and Advanced Technology for Digital Libraries, 10th European Conference, ECDL 2006, Alicante, Spain, September 17-22, 2006, Proceedings 3-540-44636-2 Julio Gonzalo Costantino Thanos M. Felisa Verdejo Rafael C. Carrasco ECDL Lecture Notes in Computer Science Springer db/conf/ercimdl/ecdl2006.html