@InProceedings{riedel2011-bionlp,
  author    = {Sebastian Riedel and David McClosky and Mihai Surdeanu and Andrew McCallum and Christopher D. Manning},
  title     = {Model Combination for Event Extraction in BioNLP 2011},
  booktitle = {Proceedings of the BioNLP Workshop},
  year      = {2011},
}