@article{anefficientmodelfreeestimationof,
  title = {An efficient model-free estimation of multiclass conditional probability},
  author = {Tu Xu and Junhui Wang},
  year = {2012},
  eprint = {1209.4951},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1209.4951v3},
}