D. Can and S.S. Narayanan, ′′A dynamic programming algorithm for computing n-gram posteriors from lattices,′′ Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing (EMNLP), pp.2388-2397, Association for Computational Linguistics, Sept. 2015. aclweb.org/anthology/D/D15/D15-1286