1. Standard methods of mechanical analysis of soils;AASHTO,1950
2. The classification of soils and soil-aggregate mixtures for highway construction purposes;AASHTO,1961
3. Progress report of the committee on significance of tests for highway materials of the highway division;ASCE;J. Highway Div. Am. Soc. Civil Eng.,1957
4. Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System);ASTM D2487-17,2017
5. Standard Practice for Classification of Soils and Soil-Aggregate Mixtures for Highway Construction Purposes;ASTM D3282- – 15,2015