Marco Gavanelli Marco Alberti Evelina Lamma Integration of Abductive Reasoning and Constraint Optimization in SCIFF. 387-401 2009 ICLP http://dx.doi.org/10.1007/978-3-642-02846-5_32 conf/iclp/2009 db/conf/iclp/iclp2009.html#GavanelliAL09