Name	Info	Provider	Link
	subscription/membership/fee required	Ingenta plc	https://www.ingentaconnect.com/openurl?genre=article&issn=&volume=21&issue=3&spage=1365&aulast=Chen
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=31922243.ui
	subscription/membership/fee required	Spandidos Publications	https://www.spandidos-publications.com/mmr/21/3/10.3892/mmr.2020.10923