Question: How do I find a DOI?

In the article/ebook itself:

• Check the very top of the first page
• Check the very bottom of the first page
• Check just before the beginning of the main text of the document
• For an ebook, it may be on the copyright page (usually follows the title page)

In the library databases:

• When searching most library databases you can click on the title of the book/article to see more information about the publication, including the DOI if one is available

Older resources may not have a DOI:

• Sources published before 2000 will not have a DOI and sources published before 2010 probably don't, but may have one
• If you can't find the DOI using the above methods, it probably doesn't have one. Most citation styles then require you to use the URL instead, but you'll need to check your citation style's requirements.

What does it look like?

A DOI usually contains a string of numbers beginning with 10.xxxx. It can appear just as those numbers, or as part of a URL. Some examples are:

• 10.1093/ajae/aaq063
• http://dx.doi.org/10.1093/ajae/aaq063