1. E. A. Guggenheim, Thermodynamics, North Holland, Amsterdam, 1957, chapter 12.
2. A. B. Pippard, Elements of Classical Thermodynamics, Cambridge University Press, Cambridge, 1957, pp. 23 and 63.
3. C. G. B. Garrett, Magnetic Cooling, Harvard University Press, Cambridge, 1954.
4. D. de Klerk and M. J. Steenland, Progr. Low Temp. Phys.
I, 273 (1955).
5. D. de Klerk, Handbuch der Physik, XV(2), 38 (1956).