Name	Info	Provider	Link
	free resource	PubMed Central	https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22195270/
	free resource	Europe PubMed Central	https://europepmc.org/abstract/MED/22195270
	free resource	Korean Urological Association	https://www.icurology.org/DOIx.php?id=10.4111/kju.2011.52.11.787