Anna E. Bobkowska Krzysztof Reszke Usability of UML Modeling Tools. 75-86 2005 Software Engineering: Evolution and Emerging Technologies series/faia/2005-130 db/series/faia/faia130.html#BobkowskaR05 http://www.booksonline.iospress.nl/Content/View.aspx?piid=1146