@inproceedings{zhu2013topic,
  title={Topic hierarchy construction for the organization of multi-source user generated contents},
  author={Zhu, Xingwei and Ming, Zhao-Yan and Zhu, Xiaoyan and Chua, Tat-Seng},
  booktitle={Proceedings of the 36th international ACM SIGIR conference on Research and development in information retrieval},
  pages={233--242},
  year={2013},
  organization={ACM}
}