Juan Carlos Nieves Mauricio Osorio Claudia Zepeda Expressing Extension-Based Semantics Based on Stratified Minimal Models. 305-319 2009 WoLLIC http://dx.doi.org/10.1007/978-3-642-02261-6_25 conf/wollic/2009 db/conf/wollic/wollic2009.html#NievesOZ09