Helge Grenager Solheim Frank M. Lillehagen Sobah Abbas Petersen Håvard D. Jørgensen Maria Anastasiou Model-Driven Visual Requirements Engineering. 421-428 2005 conf/re/2005 RE http://doi.ieeecomputersociety.org/10.1109/RE.2005.41 db/conf/re/re2005.html#SolheimLPJA05