#Forward to DOI-Resolver
RewriteCond	%{REQUEST_FILENAME}	!-d
RewriteCond	%{REQUEST_FILENAME}	!-f
RewriteRule	[dD][oO][iI]:([0-9a-zA-Z./]+)	http://dx.doi.org/$1 [redirect]

#Forward to URN-Resolver
RewriteCond	%{REQUEST_FILENAME}	!-d
RewriteCond	%{REQUEST_FILENAME}	!-f
RewriteRule	([uU][rR][nN]:[nN][bB][nN]:)(.+)	http://nbn-resolving.de/$1$2 [redirect]

#Forward to ISTC
RewriteCond	%{REQUEST_FILENAME}	!-d
RewriteCond	%{REQUEST_FILENAME}	!-f
RewriteRule	([iI][sS][tT][cC]:)(.+)	http://istc.bl.uk/search/search.html?operation=print&expand=false&locations=all&istc=$2 [redirect]

#Forward to HeBIS-OpenURL-Resolver
RewriteCond	%{REQUEST_FILENAME}	!-d
RewriteCond	%{REQUEST_FILENAME}	!-f
RewriteRule	openurl			http://linksolver.ovid.com/OpenUrl/LinkSolver?%{QUERY_STRING} [NC,redirect]