PubMed:33419461 / 7093-7222 JSONTXT

{"project":"LitCovid-sentences","denotations":[{"id":"T49","span":{"begin":0,"end":129},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Afterwards, sample points have been drawn separately per batch, following a probability proportional to size (PPS) random sample."}