3) Bjerrum, L., Kringstand, S. and Kummeneje, O.: The Shear Strength of Fine Sand, Proc. 5th Int. Conf. SMFE. Vol. 1, pp. 29-37, 1961.
4) Rowe, P. W.: The Stress-dilatancy Relation for Static Equilibrium of an Assembly of Particles in Contact, Proc. Royal Soc., London, Series A. Vol. 269. pp. 500-527, 1962.
5) Terzaghi, K. and Peck, R. B.: Soil Mechanics in Engineering Practice, p. 85, Wiley, New York. 1948.