PMC:7156291 / 1951-1963
Annnotations
LitCovid-sentences
{"project":"LitCovid-sentences","denotations":[{"id":"T25","span":{"begin":0,"end":12},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Introduction"}