1. NBR 6457: Soil Sample–Sample Preparation for Compaction and Characterisation Tests;ABNT – Brazilian Association for Technical Standards,1986
2. NBR 7181. Soil: Granulometric Analysis;ABNT – Brazilian Association for Technical Standards,1984
3. NBR 6459. Soil: Liquid Limit Determination;ABNT – Brazilian Association for Technical Standards,1984
4. NBR 7180. Soil: Plastic Limit Determination;ABNT – Brazilian Association for Technical Standards,1984
5. NBR 7182. Soil: Compaction Test;ABNT – Brazilian Association for Technical Standards,1986