Model Combination for Event Extraction in BioNLP 2011 Sebastian Riedel author David McClosky author Mihai Surdeanu author Andrew McCallum author Christopher D Manning author 2011-06 text Proceedings of BioNLP Shared Task 2011 Workshop Jun’ichi Tsujii editor Jin-Dong Kim editor Sampo Pyysalo editor Association for Computational Linguistics Portland, Oregon, USA conference publication riedel-etal-2011-model https://aclanthology.org/W11-1808/ 2011-06 51 55