Here are various semiconductor-related documents from the Hughes Aircraft Company.
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 1959 Silicon Double-Diffused Mesa Series - Description and circuit application of Hughes' double-diffused silicon mesa transistors. These were some of the first silicon types to reach several hundred megahertz, and were unusual for being PNP.
Hughes 1960 Semiconductor Products - All of Hughes' semiconductor products as well as crystal filters.
Hughes English 1960 FM Tuner - An FM tuner made to showcase Hughes' double-diffused silicon mesa transistors (see above). Note the mediocre performance and 10.5 Mc IF.
Hughes 1960 2N1228-1234, 2N1238-1244 data - Data on the Hughes PNP alloy silicon transistors. Note the low hfe.