Intel, Cpu, Semiconductors, History Of Technology.
http://www.cityu.edu.hk/phy/appkchu/AP6120/8.PDF https://www.computerhistory.org/revolution/digital-logic/12/273 https://www.computerhistory.org/siliconengine/metal-oxide-semiconductor-mos-transistor-demonstrated/ https://www.intel.com/content/www/us/en/history/museum-story-of-intel-4004.html