Journal Citation Reports (JCR) is a product from Thomson Reuters that annually publishes Journal Impact Factors (JIF); thus, JCR is the collective entry point for viewing and comparing JIF.
JCR is updated annually and appears in two editions: 'JCR Science Edition' and 'JCR Social Sciences Edition.' Both editions are divided into research categories based on the classification of journals in JCR, although one journal can feature in more than one category.
JCR is continually modified, with new journals being incorporated and others being discontinued or excluded. Journals are excluded if they feature an unnaturally high level of self-citation (see, for example, Noorden (2012) or Anderson (2012)).
Since a number of factors play a role in the computation of JIF (coverage of the database, publication practice and reference practice within individual research fields etc.), JIF comparisons should be undertaken with care – especially cross-category comparisons. Read more on Journal Impact Factors.
Students and academics at Danish universities, may have access to JCR via the university library, if it has a licence. Contact your library for more information.
Thomson Reuters Journal Citation Reports http://wokinfo.com/products_tools/analytical/jcr//
Richard Van Noorden (29 June 2012). Record number of journals banned for boosting impact factor with self-citations (Nature News Blog). http://blogs.nature.com/news/2012/06/record-number-of-journals-banned-for-boosting-impact-factor-with-self-citations.html
Kent Anderson (26 November 2012). Of Confections and Citations, Missteps and Marzipan (the Scholarly Kitchen blog) http://scholarlykitchen.sspnet.org/2012/11/26/of-confections-and-citations-missteps-and-marzipan/