@inproceedings{toutanova2002hmm,
 author = {Kristina Toutanova and H. Tolga Ilhan and Christopher D. Manning},
 booktitle = {Empirical Methods in Natural Language Processing (EMNLP)},
 title = {Extensions to HMM-based Statistical Word Alignment Models},
 url = {https://nlp.stanford.edu/pubs/toutanova2002hmm.pdf},
 year = {2002}
}