Hierarchical System Combination for Machine Translation Fei Huang author Kishore Papineni author 2007-06 text Proceedings of the 2007 Joint Conference on Empirical Methods in Natural Language Processing and Computational Natural Language Learning (EMNLP-CoNLL) Jason Eisner editor Association for Computational Linguistics Prague, Czech Republic conference publication huang-papineni-2007-hierarchical https://aclanthology.org/D07-1029/ 2007-06 277 286