@article{JMLR:v18:10-231,
  author  = {Fran{\c{c}}ois Caron and Willie Neiswanger and Frank Wood and Arnaud Doucet and Manuel Davy},
  title   = {Generalized P{\'o}lya Urn for Time-Varying Pitman-Yor Processes},
  journal = {Journal of Machine Learning Research},
  year    = {2017},
  volume  = {18},
  number  = {27},
  pages   = {1--32},
  url     = {http://jmlr.org/papers/v18/10-231.html}
}