UPAR7: A knowledge-based system for headline sentiment tagging François-Régis Chaumartin author 2007-06 text Proceedings of the Fourth International Workshop on Semantic Evaluations (SemEval-2007) Eneko Agirre editor Lluís Màrquez editor Richard Wicentowski editor Association for Computational Linguistics Prague, Czech Republic conference publication chaumartin-2007-upar7 https://aclanthology.org/S07-1094/ 2007-06 422 425