1. Charles Singer and E. A. Underwood, A Short History of Medicine, Oxford: Clarendon Press, 1962; pp. 610–622.
2. Ibid., pp. 687–693.
3. Ibid., pp. 693–697.
4. H. L. Jones, Medical Electricity, London: H. K. Lewis, 1906; p. 362.
5. W. H. Erb, Electrotherapeutics, transl. A. de Watteville, London. 1887; pp. 604–605. n. 2.