Sadzawka R., J., M. Peralta P., M. Ibarra M., J. M. Peralta A., and J. P. Fuentes E. “Chemical Characteristics of Chilean Forest Soils”. Revista Bosque, vol. 16, no. 1, June 1995, pp. 9-28, https://revistabosque.org/index.php/bosque/article/view/1270.