@article{JMLR:v18:16-499,
  author  = {Aryeh Kontorovich and Sivan Sabato and Ruth Urner},
  title   = {Active Nearest-Neighbor Learning in Metric Spaces},
  journal = {Journal of Machine Learning Research},
  year    = {2018},
  volume  = {18},
  number  = {195},
  pages   = {1--38},
  url     = {http://jmlr.org/papers/v18/16-499.html}
}