Databases! Check them to find articles dealing with your particular topic. Do a keyword search. For example: "case studies and airlines" or "case studies and management". Full-text articles and abstracts are available, depending on the journal.
Tip: Use the subject heading "case studies" in ABI/INFORM and Business Source Premier
The European Case Clearing House has international case studies available. They maintain three separate collections of case materials: Harvard Business School (HBS), University of Western Ontario (UWO) and The European Case Clearing House (ECCH). The fee is $3.15 if ordered through their office at Babson College.
Darden School of Business at the University of Virginia has searchable collection of case studies online. Abstracts and video previews are available but you must purchase any studies that you want. Verified faculty have free access to all content on the site.
searchable online. Many of these are available for purchase through Harvard
Harvard also sells cases from Babson College and Northwestern's Kellogg School of Management, among others
Harvard Business Publishing makes a great deal of money selling these for business school course packs and will not make them available to libraries. You can, however, order them directly from HBS, around $6.50 - 12.00 each
How to find them: