Ávila-Carrera, R., & Sánchez-Sesma, F. J. (2006). Scattering and diffraction of elastic P- and S-waves by a spherical obstacle: A review of the classical solution. Geofísica Internacional, 45(1), 3–21. https://doi.org/10.22201/igeof.00167169p.2006.45.1.189