Here are various documents from the Hughes Aircraft Company. Some are research reports, others describe their various specialized CRTs. These documents come from the H.W. Ulmer collection.
Hughes Prenosil 1958 The Avalanche or Regulator Diode - A summary on the Avalanche (also called Zener) diode, with expected usage and revenues. Hughes made diodes, so this looks like a justification for making Zeners. Includes a large table of all zener diodes available in 1958.
Hughes Prenosil 1958 Semiconductor Switching Devices for Power Application - Summary of non-bipolar transistor power switching devices and sample circuits using them.
Hughes Prenosil 1958 The Hall Effect and its Application - Describes the Hall effect, how to make Hall effect devices, and circuits that use them.
Hughes Prenosil 1958 Evaluation of an Experimental Regulator (Zener) Diode - An interim report on Hughes' first batches of Zener diodes. Quite detailed.
Hughes 1954 The Typotron: A Novel Character Display Storage Tube - An early, detailed technical paper on the Hughes Typotron tube. On some drawings are notes by H.W. Ulmer, whose company, Vacuum Tube Products, made these and the later Tonotron and Memotron tubes.
Hughes 1959 Direct Display Storage Tubes - A detailed description of the Hughes Tonotron, Typotron, and Memotron tubes.
Hughes 1959 Microwave Tubes - A summary data sheet of Hughes' speciality microwave tubes: a traveling-wave amplifier, two backward-wave oscillators, and two backward-wave amplifiers.
Hughes 1959 Tonotron Tubes - A summary of Hughes' Tonotron, Typotron, and Memotron tubes.