Google Scholar is a search engine that indexes the full text of scholarly literature across an array of publishing formats and scholarly fields. Released by Google for beta-testing in November 2004, the index includes virtually all peer-reviewed journals available online, except those published by Elsevier, the world's largest scientific publisher. Comparable in function to Elsevier's Scopus and Thomson ISI's subscription-based Web of Science service, though more inclusive in sources and languages. Its tagline is "Stand on the shoulders of giants".

However, you must be warned that the searching tools are actually limited. If you try to search articles published by date, the results are erratic. The number of articles can increase if you reduce the time-span of the search! Moreover, Google does not publish the list of scientific reviews it covers. It is thus impossible to know how exhaustive the search will be. More critics of Google Scholar can be found at Peter's digital reference shelf for example.

• Google Scholar website

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