Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=18341673.ui
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/18341673/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/18341673
	free resource	Wiley	https://doi.org/10.1111/j.1365-2125.2008.03158.x