An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Villalpando S, Montalvo-Velarde I, Zambrano N, García-Guerra A, Ramírez-Silva CI, Shamah-Levy T, Rivera JA.Villalpando S, et al.Salud Publica Mex. 2003;45 Suppl 4:S508-19. doi: 10.1590/s0036-36342003001000007.Salud Publica Mex. 2003.PMID: 14746045
Neufeld L, García-Guerra A, Sánchez-Francia D, Newton-Sánchez O, Ramírez-Villalobos MD, Rivera-Dommarco J.Neufeld L, et al.Salud Publica Mex. 2002 May-Jun;44(3):219-27. doi: 10.1590/s0036-36342002000300005.Salud Publica Mex. 2002.PMID: 12132319