@inproceedings{lowerboundsforpassiveandactivelearning,
  title = {Lower Bounds for Passive and Active Learning},
  author = {Maxim Raginsky and Alexander Rakhlin},
  year = {2011},
  booktitle = {NeurIPS 2011 12},
  url = {http://papers.nips.cc/paper/4325-lower-bounds-for-passive-and-active-learning},
}