Sentence and Expression Level Annotation of Opinions in User-Generated Discourse Cigdem Toprak author Niklas Jakob author Iryna Gurevych author 2010-07 text Proceedings of the 48th Annual Meeting of the Association for Computational Linguistics Jan Hajič editor Sandra Carberry editor Stephen Clark editor Joakim Nivre editor Association for Computational Linguistics Uppsala, Sweden conference publication toprak-etal-2010-sentence https://aclanthology.org/P10-1059/ 2010-07 575 584