Cathode-ray oscilloscopes and video test instruments / Tektronix Telecommunications test equipment for the Armed Forces : catalogue / Marconi Instruments N.V. Hollandsche Signaalapparaten. Enviromental testing at N.v. Hollandse Signaalapparaten Barr & Stroud. Environmental test department Bryans aeroquipment limited. Instrument test equipment Contraves. Servo/test instrument Douglas Aircraft Company. Demonstration Flight Tests Model 8A-3N #531, Report #589, October 1939
