Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=17957416.ui
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/17957416/
	subscription/membership/fee required	Springer	https://dx.doi.org/10.1007/s11606-007-0357-3
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/17957416