Access/Information
http://www.access-information.com/

BLITZ - Russian Baltic Information Center
http://feefhs.org/blitz/frgblitz.html

INFOSouth (USDA)
http://wwwfs.libs.uga.edu/#loans

GeoRef (American Geological Institute)
http://www.agiweb.org/georef/dds.html

Michigan Information Transfer Source (MITS)
http://www.lib.umich.edu/mits/

Netherlands Institute for Scientific Information Services (NIWI)
http://www.library.knaw.nl/

Research Express (University of Washington)
http://weber.u.washington.edu/~resxp/