M. Ageev, Q. Guo, D. Lagun, und E. Agichtein. Proceedings of the 34th international ACM SIGIR conference on Research and development in Information Retrieval, Seite 345--354. New York, NY, USA, ACM, (2011)
A. Troy, G. Zhang, und Y. Tian. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), Volume 4604 von Lecture Notes in Artificial Intelligence, Seite 206--219. Berlin, Heidelberg, Springer-Verlag, (2007)