Stefania Costantini Ramón P. Otero Alessandro Provetti Tran Cao Son Disjunctive Logic Programs with Inheritance Revisited. 294-302 2002 conf/ismis/2002 ISMIS http://dx.doi.org/10.1007/3-540-48050-1_33 db/conf/ismis/ismis2002.html#CostantiniOPS02