Many of the search results you find in LISTA won't be available in full-text format, but you can use the summaries and citations to locate the full articles elsewhere.  To limit your results to full-text items, select the Linked Full Text filter before submitting your search.

Look for the Access Options button below individual search results.  This indicates the full text of a document is available for viewing/download. Click on the button's arrow to view reading options.