DOI

A digital object identifier (DOI) can be used to cite and link to electronic documents. A DOI is guaranteed never to change, so you can use it to link permanently to electronic documents.
To find a document using a DOI

1. Copy the DOI of the document you want to open.

The correct format for citing a DOI is as follows: doi:10.1016/j.physletb.2003.10.071
2. Open the following DOI site in your browser:

http://dx.doi.org
3. Enter the entire DOI citation in the text box provided, and then click Go.