Limit your search to articles published before 2000 (when the DOI program started) you are more likely to get results without a DOI.
Once you have selected an article click the title to go into the detailed record and scroll down to the DOI:
If you don't see one, double check that the article does not have a DOI by looking it up on CrossRef.org. Refer to the following FAQ for more information:
What is a DOI? How do I find out if an article has a DOI?
As always, if you have additional questions or need more help feel free to contact the Help Desk at 903.566.7343 or 903.566.7342, by chat, or by email at library@uttyler.edu.