Name	Info	Provider	Link
	free resource	Public Library of Science	https://dx.plos.org/10.1371/journal.pmed.1003834
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/34662340/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/34662340
Full text from	free resource	Diposit Digital de la Universitat de Barcelona	http://hdl.handle.net/2445/181057