Persistent links, also known as "durable URLs," "direct URLs," "durls," or "purls," are permanent links to individual database articles or e-books that can then be shared via email, posted on a web page, or placed on a course site in Blackboard.
Individual databases provide their persistent links in different ways or may not provide them at all. See below for tips on where to locate persistent links and how to ensure these links will work for off-campus users. For further questions ask a librarian.
Please note that in rare cases, some e-resources may only allow a limited number of simultaneous users. Limited simultaneous user notes are attached to each resource either in the description of the resource or in the link from CLICnet. If you want to use a resource for class that has limited simultaneous users, or if you find using one is causing problems, please contact a librarian.
In order for a persistent link to work for off-campus users, the link must include the prefix http://ezproxy.stthomas.edu?url= or the embedded code string .ezproxy.stthomas.edu/.
In some cases the code string will already be part of the persistent link, but for others you will have to add it. It is up to you to identify whether or not the code string is already there.
Example of a persistent link that already includes the code:
Example of a persistent link that needs to have the Ezproxy code added:
To add the Ezproxy code, copy and paste the PURL into this box:
Labels to look for
Databases present persistent links to articles under many different labels, so look for any language that indicates permanance on an article page. Here are some common labels:
Persistent link/Permanent link/Permalink, e.g. or
Embed link, e.g.
Copy link, e.g.
Cite, e.g. or
Bookmark/Infomark, e.g. , , or
Once you locate the persistent link you will be able to copy it to paste it into your email, web page, or course site. You may need to alter it slightly, however, to make it accessible for off-campus users. See below for instructions on how to do this.
If you cannot locate a persistent link, look for a DOI or a PDF. See more information on these below.
Each database has its own HELP pages. These pages have database-specific instructions for creating PURLs.
Increasingly full-text content providers are adding DOIs, or digital object identifiers, - a unique code applied to a single article - to their resources. DOIs provide an easiest and surest way of creating durable links.
If a DOI is present as in this example,
simply copy the DOI, (i.e. 10.1111/j.1467-8527.2008.00416.x) and add it to the end of the following string:
Now the whole DOI looks like this http://dx.doi.org.ezproxy.stthomas.edu/10.1111/j.1467-8527.2008.00416.x.
By adding the http- edu string to the beginning of the DOI, you guarantee off-campus access to the article.
Enter the entire DOI citation in the proxy box provided above, and then click Go.
When a database provides a PDF (Portable Document Format) of an article, the PDF URL itself is a persistent link. Once you open the PDF, copy the URL in the browser's address bar and treat it like you would a persistent link. You will have to make sure the code string for off-campus users is embedded in the URL to make it available off-campus. If it's not there, review above for how to add it.