1. ABNT, 1984. NBR 7181-84, Soil: Granulometric Analysis.
2. ABNT, 1984. NBR 6508-84, Soil: Real Specific Mass.
3. ABNT, 1984. NBR 6459-84, Soil: Determination of the Liquid Limit.
4. ABNT, 1984. NBR 7180-84, Soil: Determination of the Plastic Limit.
5. Dana, J.D., 1978. Mineralogy Handbook (Revised by Cornelius S. Hurlburt, Translated by Rui Ribeiro Franco), Livros Técnicos e Científicos, Rio de Janeiro.