PMC:7210464 / 83983-84095 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T767","span":{"begin":0,"end":112},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"First, city and day fixed effects are removed. d¨ct=dct−1n∑cdct−1T∑tdct+1nT∑ctdct and q¨ct is defined similarly."}