E. Ferrara, O. Varol, F. Menczer, and A. Flammini. Proceedings of the first ACM Conference on Online Social Networks, page 213--222. New York, NY, USA, ACM, (2013)
H. Li, F. Xu, and H. Uszkoreit. Proceedings of the International Conference on Recent Advances in Natural Language Processing 2011 (RANLP 2011), page 660-665. RANLP 2011 Organising Committee, (2011)