Beth Brownholtz Werner Geyer Michael J. Muller Eric Wilcox David R. Millen Explorations in an activity-centric collaboration environment. 767-768 2004 conf/chi/2004a CHI Extended Abstracts http://doi.acm.org/10.1145/985921.985926 db/conf/chi/chi2004a.html#BrownholtzGMWM04