@inproceedings{niu-hirst:2004:ACL,
  author    = {Niu, Yun  and  Hirst, Graeme},
  title     = {Analysis of Semantic Classes in Medical Text for Question Answering},
  booktitle = {ACL 2004: Question Answering in Restricted Domains},
  editor = {Diego Mollá Aliod and José Luis Vicedo},
  year      = 2004,
  month     = {July},
  address   = {Barcelona, Spain},
  publisher = {Association for Computational Linguistics},
  pages     = {54--61}
}