An End-to-End Contrastive Self-Supervised Learning Framework for Language Understanding Hongchao Fang author Pengtao Xie author 2022 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal fang-xie-2022-end 10.1162/tacl_a_00521 https://aclanthology.org/2022.tacl-1.76/ 2022 10 1324 1340