chrF++: words helping character n-grams Maja Popović author 2017-09 text Proceedings of the Second Conference on Machine Translation Ondřej Bojar editor Christian Buck editor Rajen Chatterjee editor Christian Federmann editor Yvette Graham editor Barry Haddow editor Matthias Huck editor Antonio Jimeno Yepes editor Philipp Koehn editor Julia Kreutzer editor Association for Computational Linguistics Copenhagen, Denmark conference publication popovic-2017-chrf 10.18653/v1/W17-4770 https://aclanthology.org/W17-4770/ 2017-09 612 618