@article{JMLR:v17:15-135,
  author  = {Peter Kairouz and Sewoong Oh and Pramod Viswanath},
  title   = {Extremal Mechanisms for Local Differential Privacy},
  journal = {Journal of Machine Learning Research},
  year    = {2016},
  volume  = {17},
  number  = {17},
  pages   = {1--51},
  url     = {http://jmlr.org/papers/v17/15-135.html}
}