M. Storey, L. Cheng, I. Bull, and P. Rigby. CSCW '06: Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work, page 195--198. New York, NY, USA, ACM, (2006)
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)