Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=19137236.ui
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/19137236/
	subscription/membership/fee required	Springer	https://doi.org/10.1007/s00702-008-0169-6
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/19137236