Victor Chepoi Nadia Creignou Miki Hermann Gernot Salzer Deciding the Satisfiability of Propositional Formulas in Finitely-Valued Signed Logics. 100-105 2008 ISMVL http://doi.ieeecomputersociety.org/10.1109/ISMVL.2008.41 conf/ismvl/2008 db/conf/ismvl/ismvl2008.html#ChepoiCHS08