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Myhra W, Davis M, Mueller BA, Hickok D.Myhra W, et al.Am J Public Health. 1992 Feb;82(2):176-9. doi: 10.2105/ajph.82.2.176.Am J Public Health. 1992.PMID: 1739142Free PMC article.
Hickok DE, Gordon DC, Milberg JA, Williams MA, Daling JR.Hickok DE, et al.Am J Obstet Gynecol. 1992 Mar;166(3):851-2. doi: 10.1016/0002-9378(92)91347-d.Am J Obstet Gynecol. 1992.PMID: 1550152