Xinyu Zhang Nianlong Luo Dongxing Jiang Synchronous Graphic-Interaction in CSCL. 542-549 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2783&spage=542 2003 conf/icwl/2003 ICWL db/conf/icwl/icwl2003.html#ZhangLJ03