1. AASHTO. 2001. T99: Standard method of test for the moisture–density relations of soils using a 2.5-kg (5.5-lb) rammer and a 305-mm (12-in.) drop. 1st ed. American Association of State Highway and Transportation Officials (AASHTO).
2. ASTM. 2011a. Standard test method for field measurement of hydraulic conductivity limits of porous materials using two stages of infiltration from a borehole. ASTM standard D6391. ASTM International, West Conshohocken, Pa.
3. ASTM. 2011b. Standard practice for classification of soils for engineering purposes (Unified Soil Classification System). ASTM standard D2487. ASTM International, West Conshohocken, Pa.
4. ASTM. 2012. Standard test methods for laboratory compaction characteristics of soil using standard effort. ASTM standard D698. ASTM International, West Conshohocken, Pa.
5. ASTM. 2015. Standard test method for density and unit weight of soil in place by the sand-cone method. ASTM standards D1556. ASTM International, West Conshohocken, Pa.