The Science Citation Index Expanded (SCIE) is a citation index owned by Clarivate and previously by Thomson Reuters. It was created by Eugene Garfield at the Institute for Scientific Information, launched in 1964 as Science Citation Index (SCI). It was later distributed via CD/DVD and became available online in 1997, when it acquired the current name.
The indexing database covers more than 9,200 notable and significant journals, across 178 disciplines, from 1900 to the present. These are alternatively described as the world's leading journals of science and technology, because of a rigorous selection process.