Libor Behounek Ulrich Bodenhofer Petr Cintula Valverde-Style Representation Results in a Graded Framework. 153-160 2007 EUSFLAT Conf. (1) http://www.eusflat.org/publications/proceedings/EUSFLAT_2007/papers/Behounek_Libor_(167).pdf conf/eusflat/2007-1 db/conf/eusflat/eusflat2007-1.html#BehounekBC07