Name	Info	Provider	Link
	subscription/membership/fee required	HighWire	https://bjo.bmj.com/lookup/pmidlookup?view=long&pmid=19304581
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=19304581.ui
Cited by Patents in	free resource	The Lens - Patent Citations	https://www.lens.org/lens/search/patent/list?q=citation_id:19304581