Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=15305871.ui
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/15305871/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/15305871
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0953-816X&date=2004&volume=20&issue=4&spage=1025