Name	Info	Provider	Link
	free resource	Atypon	https://www.annsaudimed.net/doi/10.5144/0256-4947.2008.207?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/18500175/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/18500175