Name	Info	Provider	Link
	subscription/membership/fee required	Atypon	https://array.aami.org/doi/10.2345/0899-8205-46.4.308
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=22839991.ui
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22839991/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/22839991
	subscription/membership/fee required	Silverchair Information Systems	https://meridian.allenpress.com/bit/article-lookup/doi/10.2345/0899-8205-46.4.308