1. ASTM. D4253–00: Standard test methods for maximum index density and unit weight of soils using a vibratory table (reapproved 2006), 2006a, ASTM International, West Conshohocken, PA, USA: 15.
2. ASTM. D 4254–00: Standard test methods for minimum index density and unit weight of soils and calculation of relative density (reapproved 2006), 2006b, ASTM International, West Conshohocken, PA, USA: 9.
3. Burmister DM . The Importance and Practical Uses of Relative Density in Soil Mechanics, 1948, ASTM, Philadelphia, PA, USA, 1249–1268.