Name	Info	Provider	Link
	free resource	Ediciones Doyma, S.L.	http://www.elsevier.es/en/linksolver/pdf/pii/S0873-2159(11)00072-9
	free resource	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S0873-2159(11)00072-9
COPD	free resource	MedlinePlus Health Information	https://medlineplus.gov/copd.html