ingentaconnect.com
refseek.com
scientificcommons.org
itools.com
mapmuse.com
accurint.com
jstor.org
citeulike.org
academicjournals.org
opticsinfobase.org
getcited.org
researcherid.com
allacademic.com
blackwell-synergy.com
ingenta.com
crl.edu
academicinfo.net
cesnur.org
odysci.com
base-search.net
nasonline.org
webofknowledge.com
sciweavers.org
interfolio.com
lexisnexis.com
justia.com
genealogyplace.com
sciencedirect.com
worldcat.org
peoplefinders.com
allexperts.com
britannica.com
highbeam.com
freepatentsonline.com
uptodate.com
encyclopedia.com
scopus.com
refdesk.com
ipl.org
scirus.com
vlib.org
masterseek.com
accessmylibrary.com
geniusfind.com
netronline.com
blackbookonline.info
scholaruniverse.com
usasearch.gov
indexoftheweb.com
glin.gov