@article{201810.0301,
	doi = {10.20944/preprints201810.0301.v1},
	url = {https://doi.org/10.20944/preprints201810.0301.v1},
	year = 2018,
	month = {October},
	publisher = {Preprints},
	author = {Pei Wang and Qingjun Wu and Jiali He and Xiao Shang},
	title = {Approximation Operator Based on Neighborhood Systems},
	journal = {Preprints}
}