Espíndola, J. M., M. De la Fuente, and M. Mena. “A Gravity Model of the Colima, Mexico Region”. Geofisica Internacional 35, no. 4 (October 1, 1996): 409–414. Accessed March 13, 2025. http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/579.