Silvia Llorente Jaime Delgado Rubén Barrio Xavier Maronas Translation between XML-Based Rights Expressions Using UML and Relational Models. 61-70 2006 conf/axmedis/2006 AXMEDIS http://doi.ieeecomputersociety.org/10.1109/AXMEDIS.2006.56 db/conf/axmedis/axmedis2006.html#LlorenteDBM06