For an overview of the topic, see the Definition box under the Introduction. See the Generating JCRs Using Web of Science tab for a quick tutorial on using the library's database. For alternatives to JCR, see below:
A free and searchable database, Eigenfactor covers the natural and social sciences and "also lists newsprint, PhD theses, popular magazines and more." The Eigenfactor is included in Journal Citation Reports. It continues to be listed here for use on its own.
The website includes an interactive mapping function that shows the relationship of branches of science to each other based on the size of the field and the citations generated by the journals of the field. Rather than the "soft" categories used in Journal Citation Reports, where a journal may be located in one or more categories, Eigenfactor uses a hard category where a journal can only fit in one discipline.
Ranks publications in Google Scholar by analyzing the last five years of journal articles from websites that follow Google's inclusion guidelines as well as conference articles and preprints from a small number of manually identified sources. Excludes publications with less than 100 articles during the five-year period and those with no citations. The metrics provided are the h-index, variations of the h-index, and the i10-index.
A free source that uses data from Elsevier's SCOPUS database. Includes a "compare" feature that compares journal citation among countries. There is also a "map generator" that shows citation relationships by country.
Additional Resources
Additional Resources on Journal Citation Reports, H-Index, Journal Rankings, and Publishing:
NOTE: The article's neutrality and accuracy is disputable. Nonetheless, it contains a respectable list of print resources in its References section and a simple explanation of an h-index.
A Google Scholar Universal Gadget which enables users to search for the total number of citations of author(s). It provides a total citation count, total number of cited publications and Jorge E. Hirsch's H-Index.