Efficient Unsupervised Discovery of Word Categories Using Symmetric Patterns and High Frequency Words Dmitry Davidov author Ari Rappoport author 2006-07 text Proceedings of the 21st International Conference on Computational Linguistics and 44th Annual Meeting of the Association for Computational Linguistics Nicoletta Calzolari editor Claire Cardie editor Pierre Isabelle editor Association for Computational Linguistics Sydney, Australia conference publication davidov-rappoport-2006-efficient 10.3115/1220175.1220213 https://aclanthology.org/P06-1038/ 2006-07 297 304