What is a DOI?
DOI is a digital object identifier. It is a unique set of characters that are attached to a digital object to allow it to be found when you use a DOI resolver (search tool) on the Internet.
Where are they used?
The most common place they are found is on journal articles but they can be attached to books or any digital object. They were introduced in 2002 so they will often not be assigned to objects created prior to that date.
Where do I find them?
For journal articles, go to the PDF version of the article and look in the top left corner of the first page of the article. If available, DOIs will also be in the database record for an article.
Format of a correct DOI in APA Style:
Shortening a DOI: