To find the most relevant journal articles, it's often best to start with the recommended databases for your subject area.
You can usually limit to full text, or see the whole range of results and then use the Check for Full Text button to check for full text. 
You can also use Discover and limit to Full Text (Digital) and also Format: Academic Journals (be sure to use the Check for Full Text button to check for full text if it's not linked right in your results):


For a demonstration, watch this short video on how to limit to online content in our databases.