Biodocuments
http://www.biodocuments.net/

CAS Document Detective Service
(Chemical Abstracts Service)
http://info.cas.org/Support/detect.html

Corporate & Research Services (Georgia Tech.)
https://www.library.gatech.edu/servvisitors.htm

E.B. Harris & Associates
http://www.ebharrisassoc.com/

Research Investment
http://www.researchinvest.com

The Royal Society of Chemistry
http://www.rsc.org/lic/library.htm

Speedy Research Service
http://galis.org/srs

Virginia Technical Information Center (VTIC)
http://www.vtic.vt.edu/DocumentDelivery.html