Name	Info	Provider	Link
	subscription/membership/fee required	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/MDOI-RPC-04-2004-60-2-0761-8417-101019-ART6
Endoscopy	free resource	MedlinePlus Health Information	https://medlineplus.gov/endoscopy.html
	subscription/membership/fee required	Masson (France)	http://www.em-consulte.com/retrieve/pii/MDOI-RPC-04-2004-60-2-0761-8417-101019-ART6