To obtain a copy of a journal article that you already have a citation to:
Google Scholar (http://scholar.google.com) is a specialized search from Google that attempts to find scholarly items on the web. It finds this by searching through scanned books, publisher's databases, free online research databases (like PubMed), patents, web documents, and citations from other indexed documents.
Google Scholar can be searched with normal Google search syntax:
Results will be shown with the most cited items at the top.
Not everything found by Google Scholar is freely available on the web. If you are searching from an on-campus computer, look for 'Find it @ UT' to the right of the entry or below the entry, or a bold link to the PDF version at the right of an entry to look for full text.