TY - CONF TI - Proving copyright ownership using hard instances of computationally intractable problems AU - Armeni, S. AU - Christodoulakis, D. AU - Kostopoulos, I. AU - Stamatiou, Y. C. AU - Xenos, Michalis PY - 2001 SP - 137-145 PB - Εκδοτικός Οργανισμός Λιβάνη T2 - 8th Panhellenic Conference in Informatics Proceedings (Volume 2) ER -