Name	Info	Provider	Link
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S0248490099800732
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0248-4900&date=1997&volume=89&issue=2&spage=141