Jean-Marie Favre Dragan Gasevic Ralf Lämmel Andreas Winter 4th International Workshop on Language Engineering (ATEM 2007). 28-33 2007 MoDELS Workshops http://dx.doi.org/10.1007/978-3-540-69073-3_4 conf/models/2007w db/conf/models/models2007w.html#FavreGLW07