1. (1978) Part 1 of AASHTO, Standard Specifications for Transportation Materials and Methods of Sampling and Testing , AASHTO M 145-73: recommended practice for the classification of soils and soil-aggregate mixtures for highway construction purposes (AASHTO, Washington, D.C.) pp 184–190. American Association of State Highway and Transportation Officials.
2. (1980a) Part 19 of ASTM, 1980 Annual Book of ASTM standards , ASTM D 2487-69: standard method for classification of soils for engineering purposes (ASTM, Philadelphia), pp 374–378. American Society for Testing and Materials.
3. (1980b) Part 19 of ASTM, 1980 Annual Book of ASTM standards , ASTM D 2488-69: standard recommended practice for description of soils (visual-manual procedure) (ASTM, Philadelphia), pp 379–385. American Society for Testing and Materials.
4. Brewer R. (1964) Fabric and Mineral Analysis of Soils (Wiley, New York).
5. (1957) Site Investigations, British Standard Code of Practice CP 2001 (1957) (BSI, London). British Standards Institution.