Name	Info	Provider	Link
	subscription/membership/fee required	Wiley	https://onlinelibrary.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=0022-3573&date=1991&volume=43&issue=1&spage=51
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/jpp/article-lookup/doi/10.1111/j.2042-7158.1991.tb05449.x