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| Supplementary | Ellen Riloff and Janyce Wiebe. (2003). Learning extraction patterns for subjective expressions. In Proceedings of the Conference on Empirical Methods in Natural Language Processing (EMNLP-2003). |
| Supplementary | Peter D. Turney and Michael L. Littman. (2003). Measuring praise and criticism: Inference of semantic orientation from association. ACM Transactions on Information Systems (TOIS) , 21(4):315-346, 2003. |