GLEN: Generative Retrieval via Lexical Index Learning Sunkyung Lee author Minjin Choi author Jongwuk Lee author 2023-12 text Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing Houda Bouamor editor Juan Pino editor Kalika Bali editor Association for Computational Linguistics Singapore conference publication lee-etal-2023-glen 10.18653/v1/2023.emnlp-main.477 https://aclanthology.org/2023.emnlp-main.477/ 2023-12 7693 7704