If you are given an article citation that looks like this:
Frey, D. (1991). Learning the Ropes: My Life As a Product Champion. Harvard Business Review, 69(5), 46-52.
Here is how the find the full text:
Search for the journal title (Harvard Business Review in the example) in the search box above or on on the library's Journal Titles tab.
Find an article database that covers the year your article was written (1991 in the example).
Click Go, and on the next page that loads, navigate to the year (1991 here), then volume (69), then issue (5) of your citation.
You should see the article appear on the search list, or you can enter the title in the search box at top of that page.