1. Aitchison , M. E. Wood , C. C. 1965 Proceedings 6th International Conference on Soil Mechanics and Foundation Engineering 442 446
2. ASTM Standard D 4647-93 1998 Standard Test Methods for Identification and Classification of Dispersive Clay Soils by the Pinehole Test
3. ASTM Standard D 4221-99 1999 Standard Test Methods for Determining Dispersive Characteristics of Clay Soils by Double Hydrometer
4. ASTM Standard D 6572-00 2000 Standard Test Methods for Determining Dispersive Characteristics of clayey Soils by Crumb Test
5. British Standards BS 1377: part 5-6 1990 Soil for Civil Engineering Purposes - Determination of dispersibility