Learning Perceptually-Grounded Semantics in the L₀ Project Terry Regier author 1991-06 text 29th Annual Meeting of the Association for Computational Linguistics Association for Computational Linguistics Berkeley, California, USA conference publication regier-1991-learning 10.3115/981344.981362 https://aclanthology.org/P91-1018/ 1991-06 138 145