Katifori, A. Nikolaou, C. Platakis, M. Ioannidis, Y. Tympas, A. Koubarakis, M. Sarris, N. Tountopoulos, V. Tzoannos, E. Bykau, S. Kiyavitskaya, N. Tsinaraki, C. Velegrakis, Y., The Papyrus digital library: Discovering history in the news, Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), (6966 LNCS), 465-468, 2011,