1. Rough sets;Pawlak;International Journal of Computer Science,1982
2. A generalized definition of rough approximations based on similarity;Slowinski;IEEE Transactions on Knowledge and Data Engineering,2000
3. Rough set tolerance equality;Nieminen;Fundamenta Informaticae,1998
4. On minimal absorbent sets for some types of tolerance relations;Tentush;Bulletin of the Polish Academy of Sciences,1995
5. Y.Y. Yao, S.K.M. Wong, Generalization of rough sets using relationships between attribute values Proceedings of the Second Annual Joint Conference Information Sciences, 1995, pp. 30–33.