Jane's Encyclopedia of Aviation

Buhl C.W.3, Airsedans, Airster and Bull Pup (USA)
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   The single-seat high-performance open-cockpit Airster was a completely different design leaving the sesquiplane configuration for a braced low wing. Power was provided by a Whirlwind or Pratt & Whitney Wasp Junior engine.
   The final aircraft was the single-seat Bull Pup light monoplane powered by a 33.5 kW (45 hp) Szekely SR-3 engine.