@InProceedings{liao-grishman:2011:RANLP,
  author    = {Liao, Shasha  and  Grishman, Ralph},
  title     = {Acquiring Topic Features to improve Event Extraction: in Pre-selected and Balanced Collections},
  booktitle = {Proceedings of the International Conference Recent Advances in Natural Language Processing 2011},
  month     = {September},
  year      = {2011},
  address   = {Hissar, Bulgaria},
  publisher = {RANLP 2011 Organising Committee},
  pages     = {9--16},
  url       = {http://aclweb.org/anthology/R11-1002}
}