S. Jeffery, M. Franklin, und A. Halevy. Proceedings of the 2008 ACM SIGMOD international conference on Management of data, Seite 847--860. New York, NY, USA, ACM, (2008)
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)