@article{knowledgereductionofdynamiccovering,
  title = {Knowledge reduction of dynamic covering decision information systems with immigration of more objects},
  author = {Guangming Lang},
  year = {2015},
  eprint = {1504.00136},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1504.00136v1},
}