Name	Info	Provider	Link
Endoscopy	free resource	MedlinePlus Health Information	https://medlineplus.gov/endoscopy.html
Full Text at the institutional repository	free resource	Andalusian Health Repository	http://hdl.handle.net/10668/12976
	free resource	NCI CPTAC Assay Portal	https://assays.cancer.gov/non-CPTAC-3549
	free resource	scite Smart Citations	https://scite.ai/reports/30239316
	subscription/membership/fee required	Sheridan PubFactory	https://thejns.org/doi/10.3171/2018.4.JNS173070