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Lieberman E, Lang JM, Cohen A, D'Agostino R Jr, Datta S, Frigoletto FD Jr.Lieberman E, et al.Obstet Gynecol. 1996 Dec;88(6):993-1000. doi: 10.1016/s0029-7844(96)00359-6.Obstet Gynecol. 1996.PMID: 8942841