@inproceedings{xiang-etal-2013-enlisting, title = "Enlisting the Ghost: Modeling Empty Categories for Machine Translation", author = "Xiang, Bing and Luo, Xiaoqiang and Zhou, Bowen", editor = "Schuetze, Hinrich and Fung, Pascale and Poesio, Massimo", booktitle = "Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)", month = aug, year = "2013", address = "Sofia, Bulgaria", publisher = "Association for Computational Linguistics", url = "https://preview.aclanthology.org/fix-sig-urls/P13-1081/", pages = "822--831" }