Tomo Matsuda Naoki Shibata Keiichi Yasumoto Minoru Ito Framework for virtual collaboration emphasized by awareness information and asynchronous interaction. 997-1000 2008 ICME http://dx.doi.org/10.1109/ICME.2008.4607605 conf/icmcs/2008 db/conf/icmcs/icme2008.html#MatsudaSYI08