Journal Citation Reports is sourced from Web of Science Core Collection, the premier citation index on the Web of Science platform. Journals must undergo a rigorous evaluation by our editorial team in order to be covered in Web of Science Core Collection. We capture the cited references for all content from these journals, and we link those cited references to the cited papers. This article-level citation data is aggregated to the journal-level at the end of the year to create the indicators available in JCR. Over 11,000 titles from the Science Citation Index-Expanded and Social Sciences Citation Index are covered in JCR. The Science and Social Science editions of JCR are released annually.