1. “Electronic Digital System.”;Richards,1966
2. Physical Principles Involved in Transistor Action
3. J. E. Lilienfeld, U.S. Patent 1,745,175 (filed in 1926, issued in 1930), U.S. Patent 1,877,140 (filed in 1928, issued in 1932), and U.S. Patent 1,900,018 (filed in 1928, issued in 1933).
4. O. Heil, British Patent 439457 (filed in 1935, issued in 1935).
5. Modulation of Conductance of Thin Films of Semi-Conductors by Surface Charges