Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=19438690.ui
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=&date=2009&volume=35&issue=7&spage=1084
	subscription/membership/fee required	Wolters Kluwer	https://doi.org/10.1111/j.1524-4725.2009.01192.x