Name	Info	Provider	Link
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S0270-9139(97)00084-0
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=9021956.ui
	subscription/membership/fee required	Wiley	https://doi.org/10.1053/jhep.1997.v25.pm0009021956