PubMed:32034659 / 311-313
Annnotations
LitCovid-PAS-Enju
{"project":"LitCovid-PAS-Enju","denotations":[{"id":"EnjuParser_T55","span":{"begin":0,"end":2},"obj":"CD"}],"text":"31"}
LitCovid-TimeML
{"project":"LitCovid-TimeML","denotations":[{"id":"tok61","span":{"begin":0,"end":2},"obj":"CD"}],"text":"31"}