The Science Citation Index (SCI) is a citation index that covers a wide range of disciplines. The Science Citation Index Expanded (SCIE) is a wider version of the Science Citation Index that includes 9,000+ important journals in 177 scientific disciplines from 1900 to the present. The Science Citation Index (SCI), created by Eugene Garfield for the Institute for Scientific Information, is a citation index (ISI). The company, which was established in 1964, is now owned by Clarivate Analytics. (Previously, Thomson Reuters’ Intellectual Property and Science division). First and foremost, (two) [nine] [fourth number] The extended version (Science Citation Index Expanded) covers more than 9,200 notable and significant publications spanning 178 disciplines from 1900 to the present. SSCI stands for Social Science Citation Index, and it indexes over 3,000 scientific publications from 57 different social science disciplines. These are also recognised as the world’s leading science and technology journals due to a robust screening process.