1. Ampadu SIK (1997) The compaction characteristics of residual soils, In: Proc 3rd Int Conf on Structural Eng Analysis and Modeling, Accra, 7–11 September 1997
2. Ampadu SIK (2006) The loss of strength of an unsaturated local soil on soaking, Geotechnical Symposium, University of Rome, March 16-17, 2006 (in print)
3. ASTM D 1557-91 Standard Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort. Annual Book of ASTM Standards
4. ASTM D 1883-91 Standard Test Method for CBR of laboratory-compacted soils. Annual Book of ASTM Standards
5. ASTM D 5298-03 Standard Test Method for Measurement of Soil Potential (Suction) Using Filter Paper. Annual Book of ASTM Standards