Scopusis an abstract and citation database from Elsevier which offers a comprehensive overview of international research output in the fields of science, technology, medicine, social sciences, and arts and humanities. Updated daily, Scopus includes abstracts and cited references of over 21,800 peer-reviewed titles from more than 5,000 international publishers. Scopus includes references of all articles published since 1996. Pre-1996 records captured without references go back as far as 1823. In addition, Scopus covers extensive high-quality web sources, including around 25 million patent records from five patent offices. See the Scopus Content Coverage Guide for more details.