SSCI (Social Sciences Citation Index), a companion piece of SCI, was also founded by institute for scientific information, USA, and began to exist on 1988. It is a large-scale retrieval tool, which can be used to analyze the number of social science papers in different countries and regions in the world.
According to the official website, SSCI has collected more than 3,000 social science journals. Overlap with journals included in SCI, and include papers related to social science research in journals included in SCI.
It covers 58 social science disciplines such as anthropology, law, economics, history, geography and psychology. The types of documents collected include: research papers, book reviews, special discussions, editorials, autobiographies, letters, etc.
Ssci paper is an international core paper, comparable to sci, except that ssci is a social science citation index, liberal arts, and sci is a scientific citation index. In other words, ssci is an international paper with the level of "pyramid spire" in liberal arts. It can be said that SSCI is as important to humanities and social sciences as SCI is to science and engineering.