1. J. P. Joule, Proc. R. Soc. 58, 564 (1857).
2. F. G. Wick, Proc. Am. Acad. Arts Sci. 58, 555 (1923).
3. S. N. Zhurkov, V. I. Vettegren, I. I. Novak, and K. N. Kashinkova, Dokl. Akad. Nauk SSSR 3, 623 (1967).
4. W. Thomson (Lord Kelvin), Mathematical and Physical Papers (Cambridge University Press, London, 1890), Vol. 3, p. 63.
5. A. I. Slutsker, V. L. Gilyarov, and A. S. Luk’yanenko, Phys. Solid State 48(10), 1947 (2006).