Name	Info	Provider	Link
Pain	free resource	MedlinePlus Health Information	https://medlineplus.gov/pain.html
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=23269131.ui
Cited by Patents in	free resource	The Lens - Patent Citations Database	https://www.lens.org/lens/search/patent/list?q=reference_cited.nlp.ids.pmid:23269131
	free resource	scite Smart Citations	https://scite.ai/reports/23269131
	subscription/membership/fee required	Wolters Kluwer	https://doi.org/10.1097/CCM.0b013e3182783b72