First Author:   Daniel Ventosa-santaulària CIDE daniel@ventosa-santaularia.com   , Mexico       http://www.ventosa-santaularia.com Second Author: Manuel Gómez-zaldívar Universidad de Guanajuato manuel.gomez@ugto.org         Third Author: Lizet A Pérez CIDE lizet.perez@alumnos.cide.edu         http://