@Book{WMT:2009, editor = {Chris Callison-Burch and Philipp Koehn and Christof Monz and Josh Schroeder}, title = {Proceedings of the Fourth Workshop on Statistical Machine Translation}, month = {March}, year = {2009}, address = {Athens, Greece}, publisher = {Association for Computational Linguistics}, url = {http://www.aclweb.org/anthology/W09-04} }