Stochastic Representation of Conceptual Structure in the ATIS Task Roberto Pieraccini author Esther Levin author Chin-Hui Lee author 1991 text Speech and Natural Language: Proceedings of a Workshop Held at Pacific Grove, California, February 19-22, 1991 conference publication pieraccini-etal-1991-stochastic https://aclanthology.org/H91-1020/ 1991