1900 - present. Unlimited users.
Updated weekly. The Web of Science Core Collection is a group of databases (Science Citation Index Expanded, 1900-present; Social Sciences Citation Index, 1900-present; Arts & Humanities Citation Index, 1975-present) that together cover more than 21,000 journals across all disciplines. The Emerging Sources Citation Index (2005-present) tracks thousands of additional journals that are being considered for inclusion in the main citation indexes. Other files track references from conference proceedings (1990-present) and citations to books (2005-present).
The Web of Science platform currently also provides temporary access to several databases that are not part of the Core Collection, including Biosis Citation Index, Data Citation Index, and Zoological Record.