Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=22618916.ui
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22618916/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/22618916
	subscription/membership/fee required	Silverchair Information Systems	https://jamanetwork.com/journals/jama/fullarticle/10.1001/jama.2012.4111