Hierarchical Non-Emitting Markov Models Eric Sven Ristad author Robert G Thomas author 1997-07 text 35th Annual Meeting of the Association for Computational Linguistics and 8th Conference of the European Chapter of the Association for Computational Linguistics Association for Computational Linguistics Madrid, Spain conference publication ristad-thomas-1997-hierarchical 10.3115/976909.979666 https://aclanthology.org/P97-1049/ 1997-07 381 385