J. Hill, and C. Gutwin. GROUP '03: Proceedings of the 2003 international ACM SIGGROUP conference on Supporting group work, page 258-267. New York, NY, USA, ACM Press, (2003)
M. Steves, E. Morse, C. Gutwin, and S. Greenberg. GROUP '01: Proceedings of the 2001 International ACM SIGGROUP Conference on Supporting Group Work, page 125-134. New York, NY, USA, ACM Press, (2001)