Search Engines

Bibliographies on Mathematics - Search enabled database of citations for a large selection of mathematical specialties. Authors may add bibliographic lists or contextual references to their work.
http://liinwww.ira.uka.de/bibliography/Math/index.html

Directory of Open Access Journals - Covers many free full-text mathematics and scientific journals (most are peer reviewed).
http://www.doaj.org/

Front for the LANL ArXiv - Easiest search access to papers posted on the preeminent Los Alamos National Lab (LANL) Physics and Mathematics preprint server (arXiv).
http://front.math.ucdavis.edu/

AMS Directory of Mathematics e-Print Servers - American Mathematical Society's directory of preprint and e-print servers.
http://www.ams.org/global-preprints/

CiteSeer.ist - E-print database of mathematics and science papers with citation information. Papers may be added by specifying the URL where their files reside.
http://citeseer.ist.psu.edu/

Project Euclid - Full text access to the journal Annals of Mathematics; a limited number of other journals available through paid subscriptions to Project Euclid.
http://projecteuclid.org/

E-print Network - U.S. Department of Energy's search interface. Many options for fine tuning a search.
http://eprints.osti.gov/

Citebase Search - Experimental demonstration of the Open Citation Project. Search citations by paper or author.
http://citebase.eprints.org/cgi-bin/search

MathNet/MPRESS - Mathematics preprint search engine. Includes some European servers not covered elsewhere.
http://mathnet.preprints.org/

Hypertext Bibliography Project - Search enabled database of citations for a large selection of computer science specialties. Authors may add bibliographic lists or contextual references to their work.
http://liinwww.ira.uka.de/bibliography/Misc/HBP/

SAIL-eprints - E-Print search engine. Includes some archives not indexed by other engines (see the "Data Providers" pull-down menu). Use as a guest or register and receive free targeted alerts and other personalized features.
http://eprints.bo.cnr.it/

MathSearch - Searches a collection of mathematical and statistical preprint servers and databases.
http://www.maths.usyd.edu.au:8000/MathSearch.html