AMR-To-Text Generation with Graph Transformer Tianming Wang author Xiaojun Wan author Hanqi Jin author 2020 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal wang-etal-2020-amr 10.1162/tacl_a_00297 https://aclanthology.org/2020.tacl-1.2/ 2020 8 19 33