1. von Helmholtz, H., Über Integrale der hydrodynamischen Gleichungen, welche den Wirbelbewegungen entsprechen, J. Reine Angew. Math., 1858, vol. 55, pp. 25–55.
2. Kirchhoff, G., Vorlesungen über mathematische Physik: Vol. 1. Mechanik, Leipzig: Teubner, 1876.
3. Thomson, W., Vortex Statics, Proc. Roy. Soc. Edinburgh, 1878, vol. 9, pp. 59–73.
4. Thomson, W., Floating Magnets, Nature, 1878, vol. 18, pp. 13–14.
5. Mayer, A. M., On the Morphological Laws of the Configurations Formed by Magnets Floating Vertically and Subjected to the Attraction of a Superposed Magnet; with Notes on Some of the Phenomena in Molecular Structure Which These Experiments May Serve to Explain and Illustrate, Am. J. Sci. Arts, Ser. 3, 1878, vol. 16, no. 94, pp. 247–256.