1. Edison TA. Electrical Indicator, US307031, granted 21 October 1884.
2. Fleming JA. Improvements in instruments for detecting and measuring alternating electric current, GB 24850 dated 16 November 1904.
3. De Forrest L. Device for amplifying feeble electrical currents. US patent 841387, granted 15 January 1907.
4. Davis EA, Falconer IJ. J.J. Thomson and the Discovery of the Electron (London: Taylor and Francis, 1997), p. 139–52 have the complete report of the meeting of 30 April 1897.