In 1932, Yugoslavia issued a set of six semi-postals honoring the European Rowing Championship Races, held that year in Belgrade (Scott #B26-31). 60,000 sets were issued, and Scott '14 prices the unused set at $18.10 ($35.- for NH) .
The set has multiple market appeal among collectors in the states which comprise the former Yugoslavia, as well as Sports Topicalists.
With about 20 million citizens, the nations which comprise the former Yugoslavia are Slovenia, Croatia, Macedonia, Bosnia and Herzegovina, and Montenegro, the Federal Republic of Yugoslavia, and Kosovo (which is partially recognized). They are diverse emerging market economies, which are recovering from the depredations of war and the global financial crisis. Overall, annual GDP growth has been flat over the past 5 years.
Those interested in becoming part of an international community of stamp collectors, dealers, and investors are encouraged to join the "Stampselectors" group at Facebook. The group hosts lively discussions concerning stamp investment and practical aspects of collecting, and provides a useful venue for those who wish to buy, sell, or trade stamps.