[1] J. Adamek, H. Herrlich, G.E. Strecker, Abstract and Concrete Categories, Wiley, New York, 1990.
[2] W. Bandler, L.Kohout, Special properties, closures and interiors of crisp and fuzzy relations, Fuzzy sets and Systems, 26(3)
(1988), 317{331.
[3] R. Belohlavek, Fuzzy closure operators, Journal of Mathematical Analysis and Applications, 262 (2001), 473{489.
[4] R. Belohlavek, Fuzzy closure operators II, Soft Computing, 7(1) (2002), 53{64.
[5] R. Belohlavek, Fuzzy Relational Systems, Kluwer Academic Publishers, New York, 2002.
[6] R. Belohlavek, T. Funiokova, Fuzzy interior operators, International Journal of General Systems, 33(4) (2004), 415{430.
[7] R. Belohlavek, M. Krupka, Central points and approximation in residuated lattices, International Journal of Approximate
Reasoning, 66 (2015), 27{38.
[8] L. Biacino, G. Gerla, Closure systems and L-subalgebras, Information Sciences, 33 (1984), 181{195.
[9] L. Biacino, G. Gerla, An extension principle for closure operators, Journal of Mathematical Analysis and Applications, 198
(1996), 1{24
[10] U. Bodenhofer, M. De Cock, E.E. Kerre, Openings and closures of fuzzy preorderings:theoretical basics and applications to
fuzzy rule-based systems, International Journal of General Systems, 32(4) (2003), 343{360.
[11] K. Blount, C. Tsinakis, The structure of residuated lattices, International Journal of Algebra and Computation, 13 (2003),
437{461.
[12] J. Fang, I-fuzzy Alexandrov topologies and specialization orders, Fuzzy Sets and Systems, 128 (2007), 2359{2374.
[13] J. Fang, The relationship between L-ordered convergence structures and strong L-topologies, Fuzzy Sets and Systems, 161
(2010), 2923{2944.
[14] J . Fang, Y. Yue, L -fuzzy closure systems, Fuzzy sets and Systems, 161 (2010), 1242{1252.
[15] J. A. Goguen, L-fuzzy sets, Journal of Mathematical Analysis and Applications, 18 (1967), 145{174.
[16] P. Hajek, Metamathematices of Fuzzy Logic, Kluwer Academic Publishers, Dordrecht, 1998.
[17] S. E. Han, IS. Kim, A. P. Sostak, On approximate-type systems generated by L-relations, Information Sciences, 281 (2014),
8{20.
[18] J. Hao, Q. Li, The relationship between L-fuzzy rough set and L-topology, Fuzzy Sets and Systems, 178 (2011), 74{83.
[19] H. Herrlich, M. Husek, Galois connections categorically, Journal of Pure and Applied Algebra, 68 (1990), 165{180.
[20] U. Hohle, S.E. Rodabaugh, Mathematics of Fuzzy Sets: Logic, Topology, and Measure Theory, The Handbooks of Fuzzy Sets
Series 3, Kluwer Academic Publishers, Boston, 1999.
[21] Q. Jin, L. Q. Li, One-axiom characterizations on lattice-valued closure (interior) operators, Journal of Intelligent & Fuzzy
Systems, 31(3) (2016), 1679{1688.
[22] Q. Jin, L. Q. Li, G. W. Meng, On the relationships betwween types of L-conergence spaces, Iranian Journal of Fuzzy Systems,
13(1) (2016), 93{103.
[23] J. Kortelainen, On relationship between modified sets, topological space and rough sets, Fuzzy Sets and Systems, 61 (1994),
91{95.
[24] H. Lai, D. Zhang, Fuzzy preorder and fuzzy topology, Fuzzy Sets and Systems, 157 (2006), 1865{1885.
[25] L.Q. Li, Q. Jin, K. Hu, F.F. Zhao, The axiomatic characterizations on L-fuzzy covering-based approximation operators,
International Journal of General Systems, 46 (2017), 332{353.
[26] L. Q. Li, Q. G. Li, On enriched L-topologies: Base and subbase, Journal of Intelligent & Fuzzy Systems, 28(6) (2015),
2423{2432.
[27] Z. Li, T. Xie, Q. Li, Topological structure of generalized rough sets, Computers & Mathematics with Applications, 63 (2012),
1066{1071.
[28] Z. M. Ma, B. Q. Hu, Topological and lattice structures of L-fuzzy rough sets determined by lower and upper sets, Information
Sciences, 218 (2013), 194{204.
[29] Z. Pawlak, Rough sets, International Journal of Computing and Information Sciences, 11 (1982), 341{356.
[30] Z. Pawlak, Rough Set: Theoretical Aspects of Reasoning About Data, Kluwer Academic Publishers, Boston, 1991.
[31] Z. Pei, D. Pei, L. Zheng, Topology vs generalized rough sets, International Journal of Approximate Reasoning, 52 (2011),
231{239.
[32] J. Qiao, B. Q. Hu, A short note on L-fuzzy approximation spaces and L-fuzzy pretopological spaces, Fuzzy Sets and Systems,
312 (2017), 126{134.
[33] K. Y. Qin, Z. Pei, On the topological properties of fuzzy rough sets, Fuzzy Sets and Systems, 151 (2005), 601{613.
[34] A. M. Radzikowska, E. E. Kerre, A comparative study of fuzzy rough sets, Fuzzy Sets and Systems, 126 (2002), 137{155.
[35] A. M. Radzikowska, E. E. Kerre, Fuzzy rough sets based on residuated lattices, in: Transactions on Rough Sets II, Lecture
Notes in Computer Science, 3135 (2004), 278{296.
[36] A. A. Ramadan, L-fuzzy interior systems, Computers & Mathematics with Applications, 62 (2011), 4301{4307.
[37] A. A. Ramadan, E. H. Elkordy, M. El-Dardery, L-fuzzy approximition spaces and L-fuzzy toplogical spaces, Iranian Journal
of Fuzzy Systems, 13(1) (2016), 115{129.
[38] S.E. Rodabaugh, E.P. Klement, Topological and Algebraic Structures In Fuzzy Sets, The Handbook of Recent Developments
in the Mathematics of Fuzzy Sets, Kluwer Academic Publishers, Boston, Dordrecht, London, 2003.
[39] Y.H. She, G.J. Wang, An axiomatic approach of fuzzy rough sets based on residuated lattices, Computers & Mathematics
with Applications, 58 (2009), 189{201.
[40] A. Sostak, Basic structures of fuzzy topology, Journal of Mathematical Sciences, 78(6) (1996), 662{701.
[41] E. Turunen, Mathematics Behind Fuzzy Logic, A Springer-Verlag Co., Heidelberg, 1999.
[42] C. Y. Wang, Topological characterizations of generalized fuzzy rough sets, Fuzzy Sets and Systems, 312 (2017), 109{125.
[43] C. Y. Wang, Topological structures of L-fuzzy rough sets and similarity sets of L-fuzzy relations, International Journal of
Approximate Reasoning, 83 (2017), 160{175.
[44] C. Y. Wang, B. Q. Hu, Granular variable precision fuzzy rough sets with general fuzzy relations, Fuzzy Sets and Systems,
275 (2015), 39{57.
[45] Z. Wang, Y. Wang, K. Tang, Some properties of L-fuzzy approximation spaces based on bounded integral residuated lattices,
Information Sciences, 278 (2014), 110{126.
[46] W. Yao, S.E. Han, A Stone-type duality for sT0 stratified Alexandro L-topological spaces, Fuzzy Sets and Systems, 282
(2016), 1{20.
[47] W. Yao, B. Zhao, Kernel systems on L-ordered sets, Fuzzy Sets and Systems, 182 (2011), 101{109.
[48] D. Zhang, Fuzzy pretopological spaces, an extensitional topological extension of FTS, Chinese Annals of Mathematics, 3
(1999), 309{316.
[49] F. Zhao, Q. Jin, L. Li, The axiomatic characterizations on L-generalized fuzzy neighborhood system-based approximation
operators, International Journal of General Systems, 47(2) (2018), 155{173.
[50] F. Zhao, L. Li, Axiomatization on generalized neighborhood system-based rough sets, Soft Computing, 22(18) (2018), 6099{
6110.