1. Patterns produced by intersection of two sinusoidal curves the axes of which are at right angles to each other were first studied by Nathaniel Bowditch in 1815, and later by Jules-Antoine Lissajous in 1857–1858.
2. T. Prodromakis, C. Toumazou, L.O. Chua, Two centuries of memristor. Nat. Mater. 11, 478–481 (2012)
3. N. Hawkins, Wave form measurement, in Hawkins Electrical Guide, vol. 6, 2nd edn. (Theo. Audel and Co., New York, 1917), p. 1866, Figs. 2621–2623
4. W. Duddell, On rapid variations in the current through the direct current arc. J. Instit. Electr. Eng. 30(148), 232–267 (1900)
5. A.P. Trottor, in The Rotation of the Electric Arc. Proceedings of the Royal Society of London (Philosophical Transactions of the Royal Society, London, 1st January 1894), pp. 262–261