Name	Info	Provider	Link
	free resource	BioMed Central	https://cardiothoracicsurgery.biomedcentral.com/articles/10.1186/s13019-021-01655-z
Free full text from BORIS	free resource	Bern Open Repository and Information System	https://boris.unibe.ch/id/eprint/159717
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/34583731/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/34583731