Mikaël Barbero Frédéric Jouault Jeff Gray Jean Bézivin A Practical Approach to Model Extension. 32-42 2007 conf/ecmdafa/2007 ECMDA-FA http://dx.doi.org/10.1007/978-3-540-72901-3_3 db/conf/ecmdafa/ecmdafa2007.html#BarberoJGB07