The DOI is the digital object identifier. DOIs can be assigned to all types of digital content including scholarly materials such as articles and ebooks, datasets, and videos. The DOI system was implemented in 2000 so content published since 2000 is more likely to have a DOI and, in general, journal articles are more likely to have a DOI than other types of material including books.
To assist with finding a DOI, you can use the website CrossRef. You can input the title or author and see if a DOI is available.
