Johannes Oetsch, Hans Tompits. Gentzen-Type Refutation Systems for Three-Valued Logics with an Application to Disproving Strong Equivalence. In James P. Delgrande, Wolfgang Faber, editors, Logic Programming and Nonmonotonic Reasoning - 11th International Conference, LPNMR 2011, Vancouver, Canada, May 16-19, 2011. Proceedings. Volume 6645 of Lecture Notes in Computer Science, pages 254-259, Springer, 2011. [doi]