R. Fish, R. Kraut, and M. Leland. Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems, page 30--37. New York, NY, USA, ACM Press, (1988)
J. Campbell. GROUP '01: Proceedings of the 2001 International ACM SIGGROUP Conference on Supporting Group Work, page 3-4. New York, NY, USA, ACM Press, (2001)