Six Challenges for Neural Machine Translation Philipp Koehn author Rebecca Knowles author 2017-08 text Proceedings of the First Workshop on Neural Machine Translation Thang Luong editor Alexandra Birch editor Graham Neubig editor Andrew Finch editor Association for Computational Linguistics Vancouver conference publication koehn-knowles-2017-six 10.18653/v1/W17-3204 https://aclanthology.org/W17-3204/ 2017-08 28 39