1. ASTM D2166-06 (2006) Standard test method for unconfined compressive strength of cohesive soil. ASTM International, West Conshohocken
2. ASTM D421-85 (2007) Standard test method for dry preparation of soil samples for particle size analysis and determination of soil constants. ASTM International, West Conshohocken
3. ASTM D422-63 (2007) Standard test method for particle size analysis of soils. ASTM International, West Conshohocken
4. ASTM D4318-05 (2005) Standard test method for liquid limit, plastic limit and plasticity index of soils. ASTM International, West Conshohocken
5. ASTM D854-06 (2006) Standard test method for specific gravity of soil solids by water pycnometer. ASTM International, West Conshohocken