Name Info Provider Link
subscription/membership/fee required Ediciones Doyma, S.L. http://www.elsevier.es/en/linksolver/ft/pii/S0210-5705(12)00088-X
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/S0210-5705(12)00088-X
Gastrointestinal Bleeding free resource MedlinePlus Health Information https://medlineplus.gov/gastrointestinalbleeding.html