In PubMed @ UMSL, you have a better-than-average chance of finding free Full Text articles associated with the citations because
In Summary view, you will see a Free article or Free PMC article link whenever free full text is available. However, UMSL may also have access to articles that don't display such a link. For instance, both of the articles in the following image are available as full text through UMSL Libraries; it just took a bit more searching to find the first one.
In Abstract view, button-style links are used, making the source of the articles clear at a glance. The first one listed is usually from the publisher website and may or may not allow unpaid access to the article. For that reason, always try UMSL Article Linker or PMC Full-Text links first.
Clicking on the UMSL Article Linker button will pull up a new page. In the middle of the page, you will see a blue Full Text Online button when UMSL offers access to the article. If you don't see a Full-Text link, it's possible a librarian can find it for you in one of our databases or in our collection of printed journals. When these avenues fail, however, you can submit an Interlibrary Loan Request via the blue button or the Request ILL link on the right side of the page. You will usually receive an email with a PDF of the article within a few days. If you don't receive an email, check your spam folder.
To reduce some of your frustration, it may be worthwhile to filter your results so you only see articles that are available in Full text or Free full text.
NOTE Provided you've built time for research into your schedule, you have choices!