JUN, Y. B., & KIM, K. H. (2000). INTUITIONISTIC FUZZY IDEALS OF BCK-ALGEBRAS. International Journal of Mathematics and Mathematical Sciences, 2000(), a839-849-202. https://doi.org/10.1155/S0161171200004610
ABBAS, S. E. (2004). ON SMOOTH FUZZY SUBSPACES. International Journal of Mathematics and Mathematical Sciences, 2004(), 3587-3602-275. https://doi.org/10.1155/S0161171204401021
Qin, B. (2014). Fuzzy Approximating Spaces. Journal of Applied Mathematics, 2014(), 418-424-347. https://doi.org/10.1155/2014/405802