M. Peters, W. Ammar, C. Bhagavatula, and R. Power. Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), 1, page 1756--1765. (2017)
A. Maas, R. Daly, P. Pham, D. Huang, A. Ng, and C. Potts. Proceedings of the 49th annual meeting of the association for computational linguistics: Human language technologies-volume 1, page 142--150. Association for Computational Linguistics, (2011)
E. Clark, Y. Ji, and N. Smith. Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers), 1, page 2250--2260. (2018)
H. He, D. Barbosa, and G. Kondrak. Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), 1, page 1312--1320. (2013)