Chris Callison-Burch Miles Osborne Philipp Koehn Re-evaluation the Role of Bleu in Machine Translation Research. 2006 conf/eacl/2006 EACL http://acl.ldc.upenn.edu/E/E06/E06-1032.pdf db/conf/eacl/eacl2006.html#Callison-BurchOK06