The Centre for Science and Technology Studies (CWTS) of Leiden University investigates the development of science, technology, and science-related innovation – often by using large-scale databases of scientific publications and patents. CWTS is a leading provider of science and technology indicators and of performance and benchmark studies of scientific groups and institutes, including bibliometric mapping and network analysis of science. CWTS has developed longstanding relationships with prestigious universities and is a recognized international leader in the field of bibliometrics, scientometrics, and informetrics. The CWTS information system offers full and unrestricted access to various in-house databases such as Web of Science, Scopus, and PATSTAT.