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+ (plus sign)

The plus sign indicates that the citation counts for translated and original language versions of the same journal have been combined.

• (small bullet)

In journal rankings, the small bullet indicates that complete source data were not available for a particular title before the JCR processing deadline (usually mid-February of the JCR year).


An article is a significant item published in a journal covered by Journal Citation Reports®. Editorials, letters, news items, and meeting abstracts are usually not counted as articles because they are not generally cited. The Articles column in the table you see on the Journal Summary page or Journal page counts research articles, review articles, notes, and corrections/retractions. Articles and Reviews are counted separately in the Journal Source Data section of the Journal page.


A citation is the formal acknowledgment of intellectual debt to previously published research. It generally contains sufficient bibliographic information to uniquely identify the cited document. Information About ... Total Cites, Self-Citations.


See Citation

Cited Reference

See Citation

Cited Half-Life

Median age of the articles that were cited in the JCR year. Half of a journal's cited articles were published more recently than the cited half-life.

Cited Journal Data

Cited Journal data show how many citations a journal received in the JCR year.

Cited-Only Journals (Journals with only Cited Journal information)

Some of the journals listed in JCR are not citing journals, but are cited-only journals. This means that the references in these journals are not included in the database. This is significant when comparing journals because self-citations from cited-only journals are not included in JCR data. Self-citations often represent a significant percentage of the citations that a journal receives. Cited-only journals may be ceased journals, suspended journals, or superseded titles. Any journal that appears elsewhere in JCR, but not in the Citing Journal Listing, is a cited-only journal.

Citing Half-Life

Median age of articles cited by the journal in the JCR year.

Citing Journal Data

Citing journal data show how many citations a journal made to other journals (including itself) in the JCR year.

Immediacy Index

Average number of times an article is cited in the year it is published.

Impact Factor

Average number of times articles from the journal published in the past two years have been cited in the JCR year.


International Standard Serial Number, a unique number that identifies a journal. The format is four numbers, a hyphen (-), three numbers, and then a check character that may be a number or X. For example, 0010-4620

JCR year

The year of the JCR edition displayed in the top right-hand corner of the page. Each JCR year contains one year of citation data. You select the JCR year on the Welcome page.

Journal Title Changes

The Journal Title Changes page lists title changes occurring in the past two years (that is, the JCR year and the preceding year). The listing is in alphabetical order by journal title. To view this list, click the Journal Title Changes link on the Journal page or the Journal Summary List page.


An item is classified as a review if it meets any of the following criteria:

  • it cites more than 100 references
  • it appears in a review publication or a review section of a journal
  • the word review or overview appears in its title
  • the abstract states that it is a review or survey


A self-citation is a reference to an article from the same journal. Self-citations can make up a significant portion of the citations a journal gives and receives each year. You can compare self-citing rates and self-cited rates to supplement your journal evaluation.

Subject Category

Each journal in JCR is assigned to at least one subject category, indicating a general area of science or the social sciences. Journals may be included in more than one subject category; therefore, when comparing journals across related categories, it is possible to see the same journal title in different categories.

Total Cites

The total number of times that a journal has been cited by all journals included in the database in the JCR year.

Citations to journals listed in JCR are compiled annually from the JCR years combined database, regardless of which JCR edition lists the journal and regardless of what kind of article was cited or when the cited article was published. Each unique article-to-article link is counted as a citation.

Citations from a journal to an article previously published in the same journal are compiled in the total cites. However, some journals listed in JCR may be cited-only journals, in which case self-cites are not included.