Journal articles are NOT found in the catalogue. To find relevant journal articles you may need to search one or more databases. These databases may provide the full text or references to journal articles. Databases such as Legal Online Journals or HeinOnline are full text. Whereas AGIS or CaseBase Journal Articles will provide a reference to the article and you will need to locate the full text.
To select the appropriate index you should consider the jurisdiction and the topic. Eg if you only want Australian articles you will get more specific results if you search an Australian database.