Graph-Based Multi-Tweet Summarization using Social Signals Xiaohua Liu author Yitong Li author Furu Wei author Ming Zhou author 2012-12 text Proceedings of COLING 2012 Martin Kay editor Christian Boitet editor The COLING 2012 Organizing Committee Mumbai, India conference publication liu-etal-2012-graph https://aclanthology.org/C12-1104/ 2012-12 1699 1714