B. Kim, Q. Li, and A. Howe. WWW '06: Proceedings of the 15th international conference on World Wide Web, page 973--974. New York, NY, USA, ACM Press, (2006)
Y. Ding, X. Li, and M. Orlowska. ADC '06: Proceedings of the 17th Australasian Database Conference, page 99--107. Darlinghurst, Australia, Australia, Australian Computer Society, Inc., (2006)
Z. Huang, X. Li, and H. Chen. JCDL '05: Proceedings of the 5th ACM/IEEE-CS joint conference on Digital libraries, page 141--142. New York, NY, USA, ACM Press, (2005)
W. Geyer, J. Vogel, L. Cheng, and M. Muller. GROUP '03: Proceedings of the 2003 international ACM SIGGROUP conference on Supporting group work, page 115-124. New York, NY, USA, ACM Press, (2003)