1. Toms, B. A., Proc. First Intern. Congr. Rheology, 135, Scheveningen (1949).
2. Savins, J. G., Soc. Petrol. Eng. J., 4, 203 (1964).
3. Lumley, J. L., Appl. Mechn. Rev., 20, 1139 (1967).
4. Fabula, A. G., Lumley, J. L., and Taylor, W. D., Modern Developments in the Mechanics of Continua (Academic Press, New York, 1966).
5. Castro, W., and Square, W., Appl. Sci. Res., 18, 81 (1967).