Thinh Hung Truong Mai Hoang Dao Dat Quoc Nguyen COVID-19 Named Entity Recognition for Vietnamese. 2146-2153 2021 NAACL-HLT https://doi.org/10.18653/v1/2021.naacl-main.173 https://aclanthology.org/2021.naacl-main.173/ conf/naacl/2021 db/conf/naacl/naacl2021.html#TruongDN21