Cover of registered air letter sent from Leningrad to Asentsion (Paraguay) on August 25, 1933, via Berlin (Germany) on August 26, 1933, Friedrichshafen (Germany) on September 02, 1933 and by airship LZ 127 to Pernambuco (Brazil), than by planes of Condor Zeppelin to Paraguay. Received on September 11, 1933.