Google Scholar
Peer-reviewed & non-peer-reviewed papers, theses, books, abstracts & articles, from academic publishers, professional societies, preprint repositories, universities & other organizations.

MSN Live Search Academic
Provides citations & abstracts. Books & journal articles for which the text is not available via Live Search may be available through your library. Allows you to sort by relevance, date, author, journal or conference. Formatted citation can be exported to RefWorks, BibTex or EndNote.

BioMed Central
A collection of more than 160 peer-reviewed open access journals, in disciplines such as biochemistry, bioinformatics, cancer, and ecology. All original research articles receive rapid & thorough peer review. & are made freely and permanently accessible online immediately upon publication.

Directory of Open Access Journals
This service covers free, full text, quality controlled scientific & scholarly journals in all subjects & many languages. The journals can be browsed by title or subject & hundreds can be searched at the article level.

PubMed
PubMed is a service of the U.S. National Library of Medicine that includes over 17 million citations from MEDLINE & other life science journals for biomedical articles back to the 1950s. PubMed includes links to full text articles and other related resources.

SCIRUS
Scirus is the most comprehensive science-specific search engine on the Internet. Driven by the latest search engine technology, searching over 415 million science-specific Web pages, enabling you to quickly. Since it is limited to scientific, scholarly, technical and medical data on the Web, many of the irrelevant hits found by general search engines are eliminated. Includes reports, peer-reviewed articles, patents, pre prints and journals that other search engines miss.

BUBL LINK
A professionally-maintained directory of selected Internet resourcescovering all academic subject areas. Each site is evaluated, cataloged and described and the links aretested monthly. Hosted by the University of Strathclyde Library in Glasgow.

Infomine
Subject directory to scholarly Internet collections, developed by the Library of the University of California, Riverside.

MEL: Michigan Electronic Library
University of Michigan's subject directory of "Best of the Internet" sites selected by librarians.