@Book{WMT:2011, editor = {Chris Callison-Burch and Philipp Koehn and Christof Monz and Omar F. Zaidan}, title = {Proceedings of the Sixth Workshop on Statistical Machine Translation}, month = {July}, year = {2011}, address = {Edinburgh, Scotland}, publisher = {Association for Computational Linguistics}, url = {http://www.aclweb.org/anthology/W11-21} }