Scholar Google.Com

Check this out:

http://scholar.google.com

Works just like regular Google, except it returns published studies on

Your topic (with links to abstracts and/or full studies). It also will

return non-web materials.

Google Scholar enables you to search specifically for scholarly

literature, including peer-reviewed papers, theses, books, preprints, abstracts and technical reports from all broad areas of research. Use Google Scholar

to find articles from a wide variety of academic publishers, professional

societies, preprint repositories and universities, as well as scholarly

articles available across the web.

Just as with Google Web Search, Google Scholar orders your search

Results by how relevant they are to your query, so the most useful references

should appear at the top of the page. This relevance ranking takes into

account the full text of each article as well as the article's author,

the publication in which the article appeared and how often it has been

cited in scholarly literature. Google Scholar also automatically analyzes and

extracts citations and presents them as separate results, even if the

documents they refer to are not online. This means your search results

may include citations of older works and seminal articles that appear only

in books or other offline publications.

For more info and a FAQ, go to:

http://scholar.google.com/scholar/about.html