Where do i find the DOI number on an article or book?
You will normally find DOIs in database information about the article, on the first page of a journal article, or near the copyright notice for the item in question. If you cannot find the DOI on the item itself, you can check CrossRef to see if one exists. Below is an example of a DOI in a database information listing. (DOIs are increasingly showing up in e-books, also.)