Masahiro Inuiguchi Yukihiro Yoshioka Several Reducts in Dominance-Based Rough Set Approach. 163-175 2008 Interval / Probabilistic Uncertainty and Non-Classical Logics http://dx.doi.org/10.1007/978-3-540-77664-2_13 series/asc/2008-46 db/series/asc/asc46.html#InuiguchiY08