PubMed:32134681 / 325-338
Annnotations
LitCovid-PAS-Enju
{"project":"LitCovid-PAS-Enju","denotations":[{"id":"EnjuParser_T54","span":{"begin":0,"end":13},"obj":"JJ"}],"text":"retrospective"}
LitCovid-TimeML
{"project":"LitCovid-TimeML","denotations":[{"id":"tok61","span":{"begin":0,"end":13},"obj":"NN"}],"text":"retrospective"}