Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=37171445.ui
	free resource	Singapore Medical Association	https://doi.org/10.4103/singaporemedj.SMJ-2021-387
	free resource	Wolters Kluwer	https://doi.org/10.4103/singaporemedj.SMJ-2021-387