Go to the companies (normally, ethnic agents) that sell tickets to only a single area, and deal with only one or two airlines.....

Croatia: As you'd expect from its name, Croatia Travel Agency, of Astoria, New York (718/726-6700, croatiatravel.com), specializes in that large area of the former Yugoslavia. Under a special arrangement with the airlines involved, it can write tickets for Air France, Virgin Atlantic, and Lufthansa flights on Croatian Airlines ticket stock...See complete release