The annotation of the Central Unit in Rhetorical Structure Trees: A Key Step in Annotating Rhetorical Relations Mikel Iruskieta author Arantza Díaz de Ilarraza author Mikel Lersundi author 2014-08 text Proceedings of COLING 2014, the 25th International Conference on Computational Linguistics: Technical Papers Junichi Tsujii editor Jan Hajic editor Dublin City University and Association for Computational Linguistics Dublin, Ireland conference publication iruskieta-etal-2014-annotation https://aclanthology.org/C14-1045/ 2014-08 466 475