Alonso-Llanes, L., 		Sánchez-Colina, Gustavo, 		Martínez, Etién, 		Batista-Leyva, A., 		Toussaint, R., AND 		Altshuler, Ernesto.
"Intruder Penetration in Granular Matter Studied by Lock-In Accelerometry" <em>Revista Cubana de Física</em> [Online], Volume 33 Number 2 (4 November 2016)