Name	Info	Provider	Link
Full text from DIGITALCSIC	free resource	Digital CSIC Spanish National Research Council	http://hdl.handle.net/10261/269763
COVID-19 (Coronavirus Disease 2019)	free resource	MedlinePlus Health Information	https://medlineplus.gov/covid19coronavirusdisease2019.html
	free resource	Nature Publishing Group	https://doi.org/10.1038/s41598-021-02701-5
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/34862422/
Full Text at the institutional repository	free resource	Andalusian Health Repository	http://hdl.handle.net/10668/3808
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/34862422