Kamel Barkaoui Ana Cavalcanti Antonio Cerone Theoretical Aspects of Computing - ICTAC 2006, Third International Colloquium, Tunis, Tunisia, November 20-24, 2006, Proceedings Lecture Notes in Computer Science 4281 Springer 2006 3-540-48815-4 ICTAC db/conf/ictac/ictac2006.html