1. C. R. Darwin, Narrative of the Surveying Voyages of His Majesty's Ships Adventure and Beagle, Between the Years 1826 and 1836, Describing their Examination of the Southern Shores of South America, and the Beagle's Circumnavigation of the Globe, Journal and Remarks, 1832–1836 Vol. 3 (Henry Colburn, London, 1839), p. 44.
2. Currents carried by point-discharges beneath thunderclouds and showers
3. Low‐current temperature compensated bipolar log‐ratio amplifier