SOFSEM 2005: Theory and Practice of Computer Science 31st Conference on Current Trends in Theory and Practice of Computer Science Liptovský Ján, Slovakia, January 22-28, 2005. Proceedings - Vojtáš, Peter; Bieliková, Mária; Charron-Bost, Bernadette; Sýkora, Ondrej (Springer Berlin Heidelberg, 2005)