@article{geometriclatticestructureofcoveringand,
  title = {Geometric lattice structure of covering and its application to attribute reduction through matroids},
  author = {Aiping Huang and William Zhu},
  year = {2013},
  eprint = {1312.4232},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1312.4232v2},
}