6 special propaganda covers, franked with official stamps of the III. Reich, respectively postal stamps, to the referendum in Austria to the connection to the German Reich at the 10. April 1938, on addressed covers, partly with special cancel "at the 10. April the leader Your yes! " in different executions and partly with cancel of the "NSKK election assistance service state election administration", partly with airmail labels, condition slightly creased, partial slightly stained