M. Spiliopoulou, A. Schulz, and K. Winkler. page 215-228. S.Shaker Verlag, (2003)Proceedings der 7. Konferenz der SAS-Anwender in Forschung und Entwicklung(KSFE), 20. Februar-21. Februar 2003, Universit t Potsdam.
B. Liu, M. Hu, and J. Cheng. WWW '05: Proceedings of the 14th international conference on World Wide Web, page 342--351. New York, NY, USA, ACM, (2005)
G. Fung, J. Yu, P. Yu, and H. Lu. VLDB '05: Proceedings of the 31st international conference on Very large data bases, page 181--192. VLDB Endowment, (2005)