1. ASTM (American Society for Testing and Materials) (2020) D4647-93: Standard test method for identifification and classifification of dispersive clay soils by the pinhole test. ASTM International, West Conshohocken
2. ASTM (American Society for Testing and Materials) (2021) D4373-14: Standard test method for rapid determination of carbonate content of soils. ASTM International, West Conshohocken
3. ASTM (American Society for Testing and Materials) (2019) D4972: Standard test method for pH of soil. ASTM International, West Conshohocken
4. ASTM (American Society for Testing and Materials) (2018) D7503-18: Standard test method for measuring the exchange complex and cation exchange capacity of inorganic fine grained soils. ASTM International, West Conshohocken
5. ASTM (American Society for Testing and Materials) (2017) D6572: Standard test method for dispersive characteristics of clay soil by double hydrometer. ASTM International, West Conshohocken