1. Airo’Farulla, C. and La Rosa, G. (1977) An analysis of some factors influencing Atterberg limits determination of stiff highly fissured clays, in Proceedings of International Symposium on the Geotechnics of Structurally Complex Formations, Capri, Associazione Geotecnica Italiana, Vol. 2, pp. 23–29
2. ASTM D 422. (1999) Standard test method for particle-size analysis of soils. Annual Book of ASTM Standards (04.08), West Conshohocken, pp. 10–17
3. ASTM D 4318. (1999) Standard test method for liquid limit, plastic limit, and plasticity index of soils. Annual Book of ASTM Standards (04.08), West Conshohocken, pp. 526–538
4. Bjerrum, L. and Simons N.E. (1960) Comparison of shear strength characteristics of normally consolidated clays, in Proceedings of Conference on Shear Strength of Cohesive Clays, ASCE, Boulder, CO, pp. 711–726