Extracting Lexically Divergent Paraphrases from Twitter Wei Xu author Alan Ritter author Chris Callison-Burch author William B Dolan author Yangfeng Ji author 2014 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal xu-etal-2014-extracting 10.1162/tacl_a_00194 https://aclanthology.org/Q14-1034/ 2014 2 435 448