Sandro Pinna Simone Mauri Paolo Lorrai Michele Marchesi Nicola Serra XPSwiki: An Agile Tool Supporting the Planning Game. 104-113 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2675&spage=104 2003 conf/xpu/2003 XP db/conf/xpu/xp2003.html#PinnaMLMS03