Pengcheng Yang Lei Li 0039 Fuli Luo Tianyu Liu 0001 Xu Sun 0001 Enhancing Topic-to-Essay Generation with External Commonsense Knowledge. 2002-2012 2019 ACL (1) https://doi.org/10.18653/v1/p19-1193 https://aclanthology.org/P19-1193/ conf/acl/2019-1 db/conf/acl/acl2019-1.html#YangLLLS19