What is a DOI?
The DOI System is for indentifying content objects in the digital environment. DOI names are assigned to any entity for use on digital networks. They are used to provide current information, including where they...can be found on the Internet. Information about a digital object may change over time, including where to find it, but its DOI name will not change."
Source: http://www.doi.org/index.html
Free DOI Lookup Tool
http://www.crossref.org/guestquery/
Resolve a DOI Name
DOI Name Information and Guidelined Document
http://www.crossref.org/02publishers/doi-guidelines.pdf
Example and Instructions
(Source: CrossRef: DOI Name Information and Guidelines (pdf), June 11, 2007. Section 9: "Information for the End-User," p. 11.)
If you encounter a DOI name in text or header information, you can resolve it by embedding it in an HTTP hyperlink to the DOI proxy, which redirects the DOI name to the currently registered location for this content item. For example, doi:10.1006/jmbi.1998.2354 can be resolved as http://dx.doi.org/10.1006/jmbi.1998.2354. If you click on this link, you will arrive at the appropriate response page for this article at the Journal of Molecular Biology web site.
There you will see that the DOI name is included in article header information or on the title page. To include the DOI name in a citation to this article, you simply append it at the end, prefaced by “doi:” as follows:
Brian G. Turner, Michael F. Summers. “Structural Biology of HIV.” Journal of Molecular Biology, 285(1), pp. 1–32. doi:10.1006/jmbi.1998.2354.
Credit to: Samford University Libguide