Bala Krushna Tripathy Anirban Mitra Jaladhar Ojha On Rough Equalities and Rough Equivalences of Sets. 92-102 2008 RSCTC http://dx.doi.org/10.1007/978-3-540-88425-5_10 conf/rsctc/2008 db/conf/rsctc/rsctc2008.html#TripathyMO08