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de León-Aguirre DG, Billings DL, Ramírez-Sánchez R.de León-Aguirre DG, et al. Among authors: billings dl.Salud Publica Mex. 2008 May-Jun;50(3):258-67.Salud Publica Mex. 2008.PMID: 18516374Spanish.
Lafaurie MM, Grossman D, Troncoso E, Billings DL, Chávez S.Lafaurie MM, et al. Among authors: billings dl.Reprod Health Matters. 2005 Nov;13(26):75-83. doi: 10.1016/S0968-8080(05)26199-2.Reprod Health Matters. 2005.PMID: 16291488
Silva M, Billings DL, García SG, Lara D.Silva M, et al. Among authors: billings dl.Contraception. 2009 Jan;79(1):56-64. doi: 10.1016/j.contraception.2008.07.016. Epub 2008 Sep 18.Contraception. 2009.PMID: 19041442
Cohen J, Ortiz O, Llaguno SE, Goodyear L, Billings D, Martinez I.Cohen J, et al.Reprod Health Matters. 2005 Nov;13(26):84-92. doi: 10.1016/S0968-8080(05)26202-X.Reprod Health Matters. 2005.PMID: 16291489