PubMed:32150360 / 4198-4202
Annnotations
LitCovid-PAS-Enju
{"project":"LitCovid-PAS-Enju","denotations":[{"id":"EnjuParser_T707","span":{"begin":0,"end":4},"obj":"WRB"}],"text":"when"}
LitCovid-TimeML
{"project":"LitCovid-TimeML","denotations":[{"id":"tok772","span":{"begin":0,"end":4},"obj":"WRB"}],"text":"when"}