1. DeGroot, S. R., and Tolhoek, H. A., Proc. K. Ned. Akad. Wet., 54, B 42 (1951).
2. Guggenheim, E. A., J. Phys. Chem., 33, 842 (1929); 34, 1540 (1930).
3. DeGroot, S. R., “Thermodynamics of Irreversible Processes” (Amsterdam, 1951). Denbigh, K. G., “The Thermodynamics of the Steady State” (London, 1951).