Name	Info	Provider	Link
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23616870/
	subscription/membership/fee required	Georg Thieme Verlag Stuttgart, New York	https://www.thieme-connect.com/DOI/DOI?10.4338/ACI-2011-02-RA-0011
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/23616870