@InProceedings{zhou-EtAl:2014:Coling1,
  author    = {Zhou, Guangyou  and  Chen, Yubo  and  Zeng, Daojian  and  Zhao, Jun},
  title     = {Group Non-negative Matrix Factorization with Natural Categories for Question Retrieval in Community Question Answer Archives},
  booktitle = {Proceedings of COLING 2014, the 25th International Conference on Computational Linguistics: Technical Papers},
  month     = {August},
  year      = {2014},
  address   = {Dublin, Ireland},
  publisher = {Dublin City University and Association for Computational Linguistics},
  pages     = {89--98},
  url       = {http://www.aclweb.org/anthology/C14-1010}
}