author= {Ueffing, Nicola and Ney, Hermann},
title= {Word-Level Confidence Estimation for Machine Translation},
journal= {Computational Linguistics},
address= {Cambridge, MA, USA},
pages= {9-40},
volume= {33},
number= {1},
year= 2007,
month= mar,
publisher= {MIT Press},
pdf = {https://www-i6.informatik.rwth-aachen.de/publications/downloader.php?id=530&row=pdf}