Cube Pruning as Heuristic Search Mark Hopkins author Greg Langmead author 2009-08 text Proceedings of the 2009 Conference on Empirical Methods in Natural Language Processing Philipp Koehn editor Rada Mihalcea editor Association for Computational Linguistics Singapore conference publication hopkins-langmead-2009-cube https://aclanthology.org/D09-1007/ 2009-08 62 71