Name Info Provider Link
subscription/membership/fee required Ediciones Doyma, S.L. http://www.elsevier.es/en/linksolver/ft/ivp/0025-7753/116/612
subscription/membership/fee required Elsevier Science https://linkinghub.elsevier.com/retrieve/pii/S0025-7753(01)71922-7
Traveler's Health free resource MedlinePlus Health Information https://medlineplus.gov/travelershealth.html