PMC:7796344 / 97-122
Annnotations
LitCovid-sentences
{"project":"LitCovid-sentences","denotations":[{"id":"T3","span":{"begin":7,"end":18},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"stract\nBackground: Annual"}