Degang Chen, Wen-Xiu Zhang. The Lower and Upper Approximations of Fuzzy Sets in a Fuzzy Group. In Nikhil R. Pal, Michio Sugeno, editors, Advances in Soft Computing - AFSS 2002, 2002 AFSS International Conference on Fuzzy Systems. Calcutta, India, February 3-6, 2002, Proceedings. Volume 2275 of Lecture Notes in Computer Science, pages 502-508, Springer, 2002. [doi]
Abstract is missing.