1. Aitchison G. D. i 960 Relationships of moisture stress and effective stress functions in unsaturated soils. Proc. Cons. Pore Pressure and Suction in Soils 47-52. L o n d o n : L utterw orth.
2. Agarwal K. B. 1967 T he influence of size and orientation of samples on the undrained strength of London Clay* Ph.D . Thesis University of London.
3. Strength variations in London Clay;Bishop A. W.;Silicates Industries,1947
4. Bishop A. W. 1952 T he stability of earth dams. Ph.D. Thesis University of London.
5. Bishop A. W. 1953 Private com munication to Dr A. S. Laughton (see Skempton i 960).