Name	Info	Provider	Link
	subscription/membership/fee required	Ovid Technologies, Inc.	http://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=linkout&SEARCH=17618471.ui
	subscription/membership/fee required	Springer	https://dx.doi.org/10.1007/s10096-007-0345-x
SILVA SSU Database	free resource	SILVA	http://www.arb-silva.de/search/show/ssu/pubid/17618471