PMC:7017878 / 107-117
Annnotations
LitCovid-sentences
{"project":"LitCovid-sentences","denotations":[{"id":"T4","span":{"begin":0,"end":10},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Background"}