Sweden. Postal stationery, Double postcard, Facit bKd10, 52, Reply card 5+5 öre additionally franked with 5+5 öre, sent in both directions, the originating card from HELSINGBORG 12.2.1904 to Austria, and the response card from WIEN 3/3 16.2.04. Double usages in the international mail exchange are very scarce.
