Dorronsoro, C., y M. Delgado. «Fundamentals of a Method for Studying the Coarse Sand Fraction of Soils». Ars Pharmaceutica (Internet), vol. 11, n.º 7-10, junio de 1970, pp. 361-75, https://revistaseug.ugr.es/index.php/ars/article/view/9734.