Name	Info	Provider	Link
	free resource	J-STAGE, Japan Science and Technology Information Aggregator, Electronic	https://dx.doi.org/10.1267/ahc.09019
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/19918322/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/19918322