Angela Brunstein Josef Krems Helps and Hints for Learning with Web Based Learning Systems: The Role of Instructions. 794-796 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3220&spage=794 2004 conf/its/2004 Intelligent Tutoring Systems db/conf/its/its2004.html#BrunsteinK04