PMC:7160614 / 31785-31805
Annnotations
LitCovid-sentences
{"project":"LitCovid-sentences","denotations":[{"id":"T341","span":{"begin":0,"end":20},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"• multi-center study"}