Google scholar another great product from google was recently rolled out, It facilitates ways to find research documents from various authority sites, Visit scholar site here, scholar.google.com
This is what google says about Google Scholar,
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 availableacross 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.
Please let us know if you have suggestions, questions or comments about Google Scholar. We recognize the debt we owe to all those in academia whose work has made Google itself a reality and we hope to make Google Scholar as useful to this community as possible. We believe everyone should have a chance to stand on the shoulders of giants.