Name	Info	Provider	Link
	subscription/membership/fee required	HighWire	https://adc.bmj.com/lookup/pmidlookup?view=long&pmid=27789460
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=27789460.ui
	free resource	scite Smart Citations	https://scite.ai/reports/27789460
	free resource	Spiral, Imperial College Digital Repository	http://hdl.handle.net/10044/1/51909