WASET
	@article{(Open Science Index):https://publications.waset.org/pdf/9259,
	  title     = {The Lower and Upper Approximations in a Group},
	  author    = {Zhaohao Wang and  Lan Shu},
	  country	= {},
	  institution	= {},
	  abstract     = {In this paper, we generalize some propositions in [C.Z. Wang, D.G. Chen, A short note on some properties of rough groups, Comput. Math. Appl. 59(2010)431-436.] and we give some equivalent conditions for rough subgroups. The notion of minimal upper rough subgroups is introduced and a equivalent characterization is given, which implies the rough version of Lagranges Theorem.
},
	    journal   = {International Journal of Mathematical and Computational Sciences},
	  volume    = {6},
	  number    = {8},
	  year      = {2012},
	  pages     = {1147 - 1151},
	  ee        = {https://publications.waset.org/pdf/9259},
	  url   	= {https://publications.waset.org/vol/68},
	  bibsource = {https://publications.waset.org/},
	  issn  	= {eISSN: 1307-6892},
	  publisher = {World Academy of Science, Engineering and Technology},
	  index 	= {Open Science Index 68, 2012},
	}