Search engines are all different in the Web sites they cover, and the way they classify these Web sites.The search engines for science, focuses only on Web pages containing scientific contents, helps you quickly locate scientific information on the Web:

• Filters out non-scientific sites.
• Finds peer-reviewed articles such as PDF and PostScript files, which are often invisible to other search engines.
• Searches the most comprehensive combination of web information, preprint servers, digital archives, repositories and patent and journal databases.

• Gold Rush

Gold Rush is a tool to help you find the best databases to search for information on a specific topic or from a specific journal. Gold Rush will also help to determine whether or not you have access to a particular database. If you do have access to a database, Gold Rush will provide you with a link to search that database.

You can begin simply by entering a term in the Search Term field to the left, selecting a search type from the drop down field, then clicking "Search".

• 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 available across the web.

• Info Finder

A global link to research on agriculture, hunger, poverty and the environment.Is a collaboration between Future Harvest Centers, CGIAR (Consultative Group on International Agricultural Research ) and FAO/WAICENT which allows you to search for digital information on all three web sites. CGIAR works to promote food security, poverty eradication, and the sound management of natural resources throughout the developing world. It is the largest scientific network of its kind.

• Scirus

Scirus is the most comprehensive science-specific search engine on the Internet. Driven by the latest search engine technology, Scirus searches over 200 million science-specific Web pages, enabling you to quickly:

• Pinpoint scientific, scholarly, technical and medical data on the Web.
• Find the latest reports, peer-reviewed articles, patents, pre prints and journals that other search engines miss.
• Offer unique functionalities designed for scientists and researchers.