Document-level Relation Extraction with Dual-tier Heterogeneous Graph Zhenyu Zhang author Bowen Yu author Xiaobo Shu author Tingwen Liu author Hengzhu Tang author Wang Yubin author Li Guo author 2020-12 text Proceedings of the 28th International Conference on Computational Linguistics Donia Scott editor Nuria Bel editor Chengqing Zong editor International Committee on Computational Linguistics Barcelona, Spain (Online) conference publication zhang-etal-2020-document 10.18653/v1/2020.coling-main.143 https://aclanthology.org/2020.coling-main.143/ 2020-12 1630 1641