Cruz, Olga, and Antonio Carlos Colangelo. “Shear Strenght of the Materials Applied to the Slope Stability Analysis in a Humid Tropical Environment (São Paulo, Brasil)”. Geografia Fisica E Dinamica Quaternaria, vol. 23, no. 1, June 2000, pp. 33-41, https://gfdq.glaciologia.it/index.php/GFDQ/article/view/459.