1. AASHTO T90, Standard Method of Test for Determining the Plastic Limit and Plasticity Index of Soils;AASHTO,2020
2. AS 1289.3.1.1–2009, Methods of Testing Soils for Engineering Purposes – Soil Classification Tests – Determination of the Liquid Limit of a Soil – Four Point Casagrande Method;AS,2009
3. Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils;ASTM D4318-17e1,2017
4. Lerornas forhållande till vatten, deras plasticitetsgränser och plasticitetsgrader;Atterberg;Kungliga Lantbruksakademiens Handlingar och Tidskrift,1911
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