May 11, 2015 – The Web of Science Core Collection, composed of Science Citation Index from Thomson Web of Science , Social Sciences Citation Index from Thomson Web of Science , and Arts & Humanities Citation Index from Thomson Web of Science , now includes citations back to 1900 (from our previous start date of 1975).
The ability to search and discover earlier papers will make it easier to trace the history and evolution of ideas over time. The full file (1900 to present) includes over 32 million citations and all of this content is integrated into the same search platform with which many of our users are already familiar.
The Web of Science databases are composed differently from other abstracting and indexing databases like those from ProQuest and EBSCO. The Web of Science includes citations to articles, conference papers, and books that have been cited by other sources, not all publications from a set of journals or on a topic. If an article is exactly what you need for your research, but that article has not been cited in another publication, it will not appear in Web of Science search results. We always recommend using multiple databases when performing comprehensive research.