A. Zündorf, and J. Dreyer. Fujaba Days 2009: proceedings of the 7th international Fujaba days, page 56-58. Technische Universiteit Eindhoven, (November 2009)
M. de Marneffe, B. MacCartney, and C. Manning. Proceedings of the IEEE / ACL 2006 Workshop on Spoken Language Technology, The Stanford Natural Language Processing Group, (2006)