see also:
http://www.katzenbach.com/Work/Publications/PublicationInstance/tabid/73/Default.aspx?Entity_ID=49
excerpt: http://harvardbusinessonline.hbsp.harvard.edu/b02/en/common/viewFileNavBean.jhtml?_requestid=156314
S. Bryant, A. Forte, и A. Bruckman. GROUP '05: Proceedings of the 2005 international ACM SIGGROUP conference on Supporting group work, стр. 1--10. New York, NY, USA, ACM Press, (2005)