Open Domain Targeted Sentiment Margaret Mitchell author Jacqui Aguilar author Theresa Wilson author Benjamin Van Durme author 2013-10 text Proceedings of the 2013 Conference on Empirical Methods in Natural Language Processing David Yarowsky editor Timothy Baldwin editor Anna Korhonen editor Karen Livescu editor Steven Bethard editor Association for Computational Linguistics Seattle, Washington, USA conference publication mitchell-etal-2013-open https://aclanthology.org/D13-1171/ 2013-10 1643 1654