Name	Info	Provider	Link
	subscription/membership/fee required	Chinese Medical Association Publishing House Ltd.	https://www.yiigle.com/LinkIn.do?linkin_type=pubmed&DOI=10.3760/cma.j.issn.0253-2727.2021.01.012
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/33677871/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/33677871