Air Mail cover 1933 (5 July) special post card carried on the "Four Countries Glider Flight" to Budapest (13.7 arrival) bearing Liechtenstein 5Rp., 25Rp. and 90Rp. adhesives and cancelled at Triesenberg, showing flight cachet in violet adjacent, Zurich (8.7) and Vienna (same day) transit c.d.s.; light staining. Rare, only 112 cards flown