A "citation number" has been added to the recommended way to cite AGU articles published in 2002 and later. This addition is necessary so that the Institute of Scientific Information (ISI) can count the number of times specific articles are cited.

The AGU "citation number" is a 4-digit number that will be assigned at the time of publication; i.e., when an article is posted online. For contributions, the numbers will be sequential throughout the year within a journal or section of JGR. Special issue papers will be numbered sequentially but in a different series. The new citation number is used in addition to the DOI (Digital Object Identifier). See http://www.agu.org/pubs/e_publishing/index.html?anchor=diff for further discussion of AGU’s use of the DOI. 

Some abstracting and indexing services may call this new element by different names. For example, ISI will label it "art. no." in their Web of Science. AGU will not use that designation because for more than 20 years, "article number" has been used by AGU to designate the number that tracks an article through the production process and that identifies it after publication. This "article number" is the unique part of the DOI for an AGU article.

The spine of the printed journals starting with the August issues will show the range of citation numbers for the articles contained therein. Thus, this new element will be a further aid to finding articles in the printed issues. 

How can you be certain that you have provided a complete and accurate citation for 2002 articles?

Be sure you include both the DOI and the new citation number. Other publishers will use the DOI to link to the article. ISI will use the citation number as an aid for identifying articles when they are counting the number of citations.

Where can you find the new citation number?

The html version of the article will show the full and accurate citation. Articles published before 31 August are being updated to include this new element.

There will be online indexes by author and by DOI, which will give you the corresponding citation number. See individual journal pages.

Starting with the August issues, each printed journal will contain a consolidated author index, which will show both the new citation number and the DOI. These numbers will also appear on the table of contents.

Why wasn’t this element included in the recommended citation when AGU started publishing online 1 January 2002? On the basis of the way G-Cubed articles had been handled by ISI, AGU staff thought that ISI would be able to use the DOI, which is a unique article identifier. When it became evident that some aspects of ISI services would not operate off the DOI, the staff worked closely with ISI management and technical staff on a resolution. ISI is in the process of entering the data for AGU articles, including the new citation numbers for all articles that have been published to date.