Q. What is a DOI?

• A Digital Object Identifier (DOI) is a unique persistent identifier for a published digital object such as a journal article.

An article with a DOI will have a persistent link on Internet and will remain accessible even if a journal changes its URL or ceases publishing. 

 The International DOI Foundation manages the DOI system.

• What if you don't see a DOI on the article? You can look it up on Crossref, the registration agency for most DOIs. DataCite is another DOI registration agency.