X. Wen, Y. Lin, C. Trattner, and D. Parra. Proceedings of the 25th ACM Conference on Hypertext and Social Media, page 285--290. New York, NY, USA, ACM, (2014)
H. Ji, and R. Grishman. Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies - Volume 1, page 1148--1158. Stroudsburg, PA, USA, Association for Computational Linguistics, (2011)