Name	Info	Provider	Link
	subscription/membership/fee required	Ingenta plc	https://www.ingentaconnect.com/openurl?genre=article&issn=1792-1074&volume=4&issue=5&spage=965&aulast=DU
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23162632/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/23162632