Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=20680375.ui
	subscription/membership/fee required	Springer	https://dx.doi.org/10.1007/s10165-010-0341-3
	subscription/membership/fee required	Taylor & Francis	https://www.tandfonline.com/doi/full/10.1007/s10165-010-0341-3
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/mr/article-lookup/doi/10.1007/s10165-010-0341-3