@article{s2anefficientgraphbasedactivelearning,
  title = {S2: An Efficient Graph Based Active Learning Algorithm with Application to Nonparametric Classification},
  author = {Gautam Dasarathy and Robert Nowak and Xiaojin Zhu},
  year = {2015},
  eprint = {1506.08760},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1506.08760v1},
}