Finding a DOI
A DOI (digital object identifier) is a string of numbers and letters assigned to an electronic publication. It serves as a permanent link to the source.
Find it
It is found near the publication information at the top of an article or on the full item record in a database.

Search it
With just the DOI number, you can search for an article on Library Search or another search engine. This is especially helpful if you find a source in another publication’s reference list and want to access it.

If the article does not come up in Library Search, try searching the number on doi.org.
Cite it
When citing an electronic article, use the DOI (when available) in place of the URL to document the location of the source or as required by the particular citation style you are using
Otranto, Domenico, et al. “The Enigma of the Dog Mummy from Ancient Egypt and the Origin of ‘Rhipicephalus sanguineus.’” Parasites & Vectors, vol. 7, no. 2, 20 Jan. 2014. BioMed Central, doi: 10.1186/1756-3305-7-2.