Salvatore Greco Benedetto Matarazzo Roman Slowinski Fuzzy Set Extensions of the Dominance-Based Rough Set Approach. 239-261 2008 Fuzzy Sets and Their Extensions: Representation, Aggregation and Models http://dx.doi.org/10.1007/978-3-540-73723-0_13 series/sfsc/2008-220 db/series/sfsc/sfsc220.html#GrecoMS08