PMC:7166305 / 139-151
Annnotations
LitCovid-sentences
{"project":"LitCovid-sentences","denotations":[{"id":"T4","span":{"begin":2,"end":12},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"t\nBackground"}