Andrzej Jankowski Andrzej Skowron Toward Rough-Granular Computing. 1-12 2007 conf/rsfdgrc/2007 RSFDGrC http://dx.doi.org/10.1007/978-3-540-72530-5_1 db/conf/rsfdgrc/rsfdgrc2007.html#JankowskiS07