Learning Bigrams from Unigrams Xiaojin Zhu author Andrew B Goldberg author Michael Rabbat author Robert Nowak author 2008-06 text Proceedings of ACL-08: HLT Johanna D Moore editor Simone Teufel editor James Allan editor Sadaoki Furui editor Association for Computational Linguistics Columbus, Ohio conference publication zhu-etal-2008-learning-bigrams https://aclanthology.org/P08-1075/ 2008-06 656 664