Name	Info	Provider	Link
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S1743-6095(15)33244-6
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=20955310.ui
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=&date=2011&volume=8&issue=1&spage=213
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/jsm/article-lookup/doi/10.1111/j.1743-6109.2010.02074.x