Optimizing Statistical Machine Translation for Text Simplification Wei Xu author Courtney Napoles author Ellie Pavlick author Quanze Chen author Chris Callison-Burch author 2016 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal xu-etal-2016-optimizing 10.1162/tacl_a_00107 https://aclanthology.org/Q16-1029/ 2016 4 401 415