Before revision: Michael Riordan, Lillian Hoddeson (1998) Crystal Fire: The Invention of the Transistor and the Birth of the Information Age, p. 89-93 In 1930 Bernhard Gudden and Wilson established that electrical conduction in semiconductors was due to trace impurities in the crystal , a .
After revision: Michael Riordan, Lillian Hoddeson (1998) Crystal Fire: The Invention of the Transistor and the Birth of the Information Age, p. 89-93 In 1930 Bernhard Gudden and Wilson established that electrical conduction in semiconductors was due to trace impurities in the crystal .