Black Box Features for the WMT 2012 Quality Estimation Shared Task Christian Buck author 2012-06 text Proceedings of the Seventh Workshop on Statistical Machine Translation Chris Callison-Burch editor Philipp Koehn editor Christof Monz editor Matt Post editor Radu Soricut editor Lucia Specia editor Association for Computational Linguistics Montréal, Canada conference publication buck-2012-black https://aclanthology.org/W12-3109/ 2012-06 91 95