Name	Info	Provider	Link
	subscription/membership/fee required	Ediciones Doyma, S.L.	http://www.archbronconeumol.org/en/linksolver/ft/pii/S0300-2896(21)00065-X
	free resource	Elsevier Science	https://linkinghub.elsevier.com/retrieve/pii/S0300-2896(21)00065-X
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/34629656/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/34629656
	subscription/membership/fee required	ClinicalKey	https://www.clinicalkey.com/content/playBy/pii?v=S0300-2896(21)00065-X
Full text from	free resource	Diposit Digital de la Universitat de Barcelona	http://hdl.handle.net/2445/183987