Name	Info	Provider	Link
	subscription/membership/fee required	Atypon	https://journals.physiology.org/doi/10.1152/ajpgi.1986.251.3.G398?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub 0pubmed
Iron	free resource	MedlinePlus Health Information	https://medlineplus.gov/iron.html