PubMed Central® Releases New Search Option for Embargoed Articles

[Editor's note added November 25, 2009: Please note that the PMC search option only includes articles with an initial embargo of up to twelve months. Articles with an embargo greater than twelve months are not compliant with the NIH Public Access Policy and will appear in search results only when the full text is free in PMC.]

F inding embargoed article citations in PubMed Central (PMC) is now as easy as 1-2-3! [Note: "Embargoed" articles comprise those which are not immediately free on publication, but only after a specified time period.] With the implementation of a new PMC search option, you can easily retrieve both the citations for embargoed articles and their corresponding PMC reference numbers, known as PMCIDs. Because articles under embargo do not show up during a regular PMC search, this new feature is particularly valuable for authors and publishers who must submit PMCIDs as proof of compliance with the National Institutes of Health Public Access Policy.

1. Take it to the "Limits"
   To locate the new search option from the PMC homepage, click on Advanced search (see Figure 1).
   
   
   
   Figure 1: Choose Advanced search from the PMC homepage.
   Next, click on the Limits tab at the top of the PMC search page (see Figure 2).
   
   
   
   Figure 2: PMC Search Page.
2. Ready, Set, Search
   Once you are on the Limits page, click in the field, "Show both free and embargoed articles." and enter your search and click Go (see Figure 3).
   
   
   
   Figure 3: Search for Free and Embargoed Articles.
   Next, take a look at the search results on the Summary display page (see Figure 4), where you can now see three tabs, "All," "Free," and "Embargoed," as well as the number of articles in each of these categories. These display features will allow you to obtain an immediate view of the number of Free vs. Embargoed articles within your initial search result.
   
   
   
   Figure 4: Results Page with Tabs for Free and Embargoed Article Citations.
3. Your Number is Up!
   Finally, click on the "Embargoed" tab at the top of the Results Page. As shown in Figure 5, you will then be able to find the PMCID at the bottom of an article citation, as well as the date on which the article itself becomes publicly available or "Free in PMC." Please note that the usual PMC links, such as "Full Text," will not appear with the citation until the article is viewable in PMC.
   
   
   
   Figure 5: Embargoed Article PMCID and Date of Availability.

By Marla Fogelman
National Center for Biotechnology Information

Fogelman M. PubMed Central® Releases New Search Option for Embargoed Articles. NLM Tech Bull. 2009 Sep-Oct;(370):e8.