Research and advanced technology for digital libraries : International Conference on Theory and Practice of Digital Libraries, TPDL 2013, Valletta, Malta, September 22-26, 2013. Proceedings - Papatheodorou, Christos; Dobreva, Milena; Tsakonas, Giannis; Farrugia, Charles J.; Aalberg, Trond (Lecture Notes in Computer Science, 2013)