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2. BS 1377-2 (1990) Methods of test for soils for civil engineering purpose-part 2: classification tests. British Standards Institution (BSI), London
3. BS 1377 (1990) British Standard BS1377: methods of test for soils for civil engineering purposes. British Standards Institution (BSI), London
4. BS 5930 (1981) Code of practice for site investigations. British Standards Institution (BSI), London
5. Burland JB (1989) Small is beautiful: the stiffness of soils at small strains. Ninth Laurits Bjerrum Lecture. Can Geotech J 26(4):499–516