Name	Info	Provider	Link
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/30539106/
	free resource	Georg Thieme Verlag Stuttgart, New York	https://www.thieme-connect.com/DOI/DOI?10.1055/s-0043-119090
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/30539106