What is a DOI? How do I find one?
Answer
DOI stands for Digital Object Identifier, a system used to identify content online. A DOI is a unique number assigned to items, like scholarly articles, on the Web. A DOI looks like this:
Use DOI to find citation
If you have a DOI but not the citation information, you can look up the citation at DOI.org. For example, if you paste the DOI above into the search box on DOI.org, it will retrieve this citation:
The Lancet, Volume 373, Issue 9663, Pages 575-581
S. Lamb, J. Marsh, J. Hutton, R. Nakash, M. Cooke
Find a DOI
If you have an article citation without a DOI, you can look up the DOI at CrossRef.org. For example, if you enter the citation information above into the CrossRef.org form, it will retrieve the DOI:
No DOI?
Some citation styles, such as APA, now require DOIs in references to electronic articles. However, some articles and journals do not provide DOIs. It is the publisher's preference to include or not include a DOI. When citing an article without a DOI, check the style manual (APA, AMA, ect.) for guidance.