Authors: Ximena Duque; Sergio Flores-Hernández; Samuel Flores-Huerta; Ignacio Méndez-Ramírez; Sergio Muñoz; Bernardo Turnbull; Gloria Martínez-Andrade; Rosa I Ramos; Marco González-Unzaga; María E Mendoza; Homero Martínez Journal: BMC Public Health Date: 2007-11-30 Impact factor: 3.295