Name	Info	Provider	Link
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0378-1097&date=1990&volume=54&issue=1-3&spage=333
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/femsle/article-lookup/doi/10.1016/0378-1097(90)90308-d