PubMed:32064855 / 709-711
Annnotations
LitCovid-PAS-Enju
{"project":"LitCovid-PAS-Enju","denotations":[{"id":"EnjuParser_T137","span":{"begin":0,"end":2},"obj":"CD"}],"text":"31"}
LitCovid-TimeML
{"project":"LitCovid-TimeML","denotations":[{"id":"tok142","span":{"begin":0,"end":2},"obj":"CD"}],"text":"31"}