Name	Info	Provider	Link
Vitamin A	free resource	MedlinePlus Health Information	https://medlineplus.gov/vitamina.html
Cited by Patents in	free resource	The Lens - Patent Citations	https://www.lens.org/lens/search/patent/list?q=citation_id:12450904
	subscription/membership/fee required	Silverchair Information Systems	https://academic.oup.com/ajcn/article-lookup/doi/10.1093/ajcn/76.6.1358