@article{relatedfamilybasedattributereductionof,
  title = {Related family-based attribute reduction of covering information systems when varying attribute sets},
  author = {Guangming Lang},
  year = {2017},
  eprint = {1711.07321},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1711.07321v1},
}