Name	Info	Provider	Link
	subscription/membership/fee required	AEPress, s r. o.	http://www.aepress.sk/_downloads/dl.php?from=pubmed&journal=AV&file=2007_01_69.pdf
SILVA SSU Database	free resource	SILVA	http://www.arb-silva.de/search/show/ssu/pubid/17432949