1. Callen, H. B. (1985).Thermodynamics, 2nd ed., Wiley, New York, Chapter 2.
2. Galgani, L., and Scotti, A. (1970).Pure and Applied Chemistry,22, 229.
3. Gibbs, J. W. (1902).Elementary Principles in Statistical Mechanics, Yale University Press, New Haven, Connecticut, p. 104.
4. Greene, R. F., and Callen, H. B. (1951).Physical Review,83, 1231.
5. Hardy, G. H., Littlewood, J. E., and Pólya, G. (1952).Inequalities, 2nd ed., Cambridge University Press, Cambridge, p. 77.