PubMed:31967327 / 345-357
Annnotations
LitCovid-PAS-Enju
{"project":"LitCovid-PAS-Enju","denotations":[{"id":"EnjuParser_T61","span":{"begin":0,"end":12},"obj":"NN"}],"text":"introduction"}
LitCovid-TimeML
{"project":"LitCovid-TimeML","denotations":[{"id":"tok66","span":{"begin":0,"end":12},"obj":"NN"}],"text":"introduction"}