R. Reichart, and A. Rappoport. Proceedings of the Thirteenth Conference on Computational Natural Language Learning, page 165--173. Morristown, NJ, USA, Association for Computational Linguistics, (2009)
C. Cattuto, D. Benz, A. Hotho, and G. Stumme. The Semantic Web -- ISWC 2008, volume 5318 of Lecture Notes in Computer Science, page 615--631. Berlin/Heidelberg, Springer, (2008)