Revisiting optimal decoding for machine translation IBM model 4, Sebastian Riedel and James Clarke, Joint Human Language Technology Conference/Annual Meeting of the North American Chapter of the Association for Computational Linguistics (HLT-NAACL '09) 2009 [pdf]
@inproceedings{riedel09revisiting,
    address={Morristown, NJ, USA}, 
    year={2009}, 
    author={Sebastian Riedel and James Clarke}, 
    bdsk-url-1={http://l2r.cs.uiuc.edu/~danr/Papers/RiedelCl09.pdf}, 
    title={Revisiting optimal decoding for machine translation IBM model 4}, 
    pages={5--8}, 
    publisher={Association for Computational Linguistics}, 
    location={Boulder, Colorado}, 
    booktitle={Joint Human Language Technology Conference/Annual Meeting of the North American Chapter of the Association for Computational Linguistics (HLT-NAACL '09)}, 
}