What is a DOI and how can I find it?
DOI stands for Digital Object Identifier. A DOI is a string of numbers, letters and symbols used to permanently identify an article or document and link to it on the web. You can think of a DOI as a Social Security Number for an article. Unlike URLs, DOIs never change.
This is what a DOI looks like: 10.2522/ptj.20090278
You can create a link out of a DOI by adding the prefix: doi.org/
Here is a list of common places where you can find the DOI for an article:
- First page of the electronic journal article
- Near the copyright notice
- Database landing page for an article
- In the citation generated by the database
- Online using the free DOI lookup
If you have a DOI and want to find the article, you can use the International DOI Foundation's Resolve a DOI Name feature.
Many citation styles prefer using DOIs over URLs to link back to an article because DOIs are more permanent. If you need help citing a source, check out our Citation Help guide.