Scopus is the largest abstract and citation database of peer-reviewed literature, with bibliometrics tools to track, analyze  and visualize research.  It contains 22000 titles from more than 5000 publishers around the world, covering the fields of science, technology, medicine, social sciences, and Arts and Humanties . Scopus has 55 million records  dating back to  1823 , 84% of these contain references dating back to 1996.