You can find case studies using the database:
When searching, use the term "case review" and any topic you would like to focus on. For example, you could search for "case review" AND Starbucks.
You can also search specifically in publications such as Harvard Business Review. Once in the database, in the top blue bar, click on "Publications." Then search for your journal title and click on it once it appears. From there, you can browse by publication year or search within the publication.
Always remember to check the checkbox for "Full-Text" so your results only include articles you can access in full-text.