PENS: A Machine-aided English Writing System for Chinese Users Ting Liu author Ming Zhou author Jianfeng Gao author Endong Xun author Changning Huang author 2000-10 text Proceedings of the 38th Annual Meeting of the Association for Computational Linguistics Association for Computational Linguistics Hong Kong conference publication liu-etal-2000-pens 10.3115/1075218.1075285 https://aclanthology.org/P00-1067/ 2000-10 529 536