Answered By: Lydia Dawe
Last Updated: Sep 25, 2018     Views: 868

A digital object identifier (DOI) is a unique alphanumeric string assigned by a registration agency (the International DOI Foundation) to identify content and provide a persistent link to its location on the Internet. 

Not all journal articles have DOIs, particularly older journal articles and articles from lesser-known journals. However, more and more articles are now assigned a DOI.  All DOI numbers begin with a 10 and contain a prefix and a suffix separated by a slash ( http://dx.doi.org/10.1177/0392192109355525).

DOIs usually appear on the first page of the article itself, or they can appear on the page of the database which has the full text article linked. If you really want to know if an article has a DOI, use the CrossRef Metadata search engine.