@InProceedings{ren-EtAl:2013:SIGDIAL,
  author    = {Ren, Hang  and  Xu, Weiqun  and  Zhang, Yan  and  Yan, Yonghong},
  title     = {Dialog State Tracking using Conditional Random Fields},
  booktitle = {Proceedings of the SIGDIAL 2013 Conference},
  month     = {August},
  year      = {2013},
  address   = {Metz, France},
  publisher = {Association for Computational Linguistics},
  pages     = {457--461},
  url       = {http://www.aclweb.org/anthology/W13-4071}
}